Crock Pot French Onion Soup in just 6 simple steps!

Crock Pot French Onion Soup has a rich, savory broth filled with caramelized onions, that’s topped with melted cheese and crispy bread. Treat your taste buds!

A bowl of French onion soup topped with melted cheese and crostini.


The depth of flavor in this Crock Pot French Onion Soup broth comes from slow-cooked onions, yielding a sweet undertone. The melted cheese forms a gooey layer and adds a creamy texture. The crispy bread soaks up the flavorful liquid, creating a perfect harmony of textures and tastes. It’s a comfort food classic!

Ingredients

For Crock Pot French Onion Soup, gather onions, beef broth, butter, thyme, and baguette. Top it off with Gruyere cheese for a delectable, classic creation!

  • Onions: Provide a sweet depth when caramelized.
  • Beef Broth: Forms the flavorful base of the soup.
  • Butter: Enhances richness and adds a velvety texture.
  • Thyme: Infuses earthy, herby notes for complexity.
  • Baguette: Adds texture, especially when toasted.
  • Gruyere Cheese: Melts into a gooey topping, elevating the dish with its nutty flavor.
A pan with caramelized Onions simmering in beef broth.

How to Make Crock Pot French Onion Soup

To make Crock Pot French Onion Soup, sauté caramelized onions, simmer in beef broth, and top with a baguette slice and melted Gruyere cheese. A comforting classic!

  1. Melt butter and oil in a skillet. Add onions, and sauté until soft. Reduce heat, and cook until browned – up to 30 mins (this step can be done the night before if needed).
  2. Add garlic, sauté 1-2 mins. Stir in flour, cook 1 min. Transfer to crock pot.
  3. Deglaze skillet with cognac and wine, and boil for 2 mins. Pour into crock pot.
  4. Add cooking stock, bay leaves, thyme, and parsley to the crock pot. Cover, and cook on low for 6-8 hours or high for 4-6 hours.
  5. Discard bay leaves, thyme, and parsley when done.
  6. Preheat broiler. Ladle soup into oven-safe bowls. Top with bread and cheese. Broil for 2-4 mins until cheese melts. Serve.

Why this recipe works

Your family will love this Crock Pot French Onion Soup because it offers a comforting blend of sweet caramelized onions, rich broth, and a cheesy, crispy topping. The layered flavors and contrasting textures create a satisfying and memorable dining experience, making it a delightful and heartwarming dish for family gatherings.

  1. Caramelization: Slow-cooking onions creates a rich, sweet flavor base, enhancing the overall taste of the soup.
  2. Layered Flavors: The addition of garlic, cognac (optional), and white wine contributes complexity, elevating the taste profile.
  3. Textural Contrast: From the crispy baguette slices to the gooey melted cheese, the recipe provides a delightful interplay of textures, enhancing the overall dining experience.

Recipe tips and kitchen tricks

My kitchen tips and tricks are designed to simplify the cooking process, enhance flavors, and save time. By incorporating these suggestions, you’ll likely experience more efficient meal preparation, improved dish outcomes, and a better overall cooking experience. The goal is to make your time in the kitchen enjoyable and rewarding while achieving delicious results.

  1. Caramelization Control: To avoid burning while caramelizing onions, maintain a medium-low heat and stir frequently. Achieve the perfect sweet depth without bitterness.
  2. Deglazing Perfection: When deglazing with wine, use a wooden spoon to scrape up browned bits for added flavor. Cook until the onions are almost dry, ensuring a rich base.
  3. Broiling Brilliance: For the final touch, when broiling the soup, place oven-safe bowls on a rimmed baking sheet [paid link] for easy handling. This ensures even melting of the cheese without a mess in the oven.
Close up of a bowl of French onion soup.

Recipe Variations

Recipe variation adds variety to your culinary repertoire, keeping meals exciting and catering to different tastes. It allows for personalization, adapting the dish to dietary preferences, ingredient availability, or cultural influences. Exploring variations also sparks creativity, helping you discover unique flavors and textures, and making the cooking experience more enjoyable and satisfying.

  1. Classic Beefy Twist: Enhance the soup with diced cooked beef or shredded short ribs for a heartier, meaty version.
  2. Turkey and Sage Delight: Substitute chicken or turkey broth for a lighter flavor. Infuse sage during the cooking process for a unique twist.
  3. Vegetarian Bliss: Replace beef broth with vegetable broth. Add mushrooms for an earthy note and use a blend of cheeses like Gruyere and Swiss. This vegetarian option maintains the soup’s depth and richness.
  4. Gluten-Free Onion Soup: Ensure the broth and all ingredients are gluten-free, and choose a gluten-free baguette or croutons for the topping.

Serving Suggestions

  1. Gourmet Garnishes: Sprinkle freshly chopped chives or parsley on top for a burst of freshness and a pop of color.
  2. Citrus Zest Infusion: Grate a bit of lemon or orange zest over each serving to add a citrusy brightness that complements the savory flavors.
  3. Side of Greens: Serve the soup alongside a crisp green salad with a light vinaigrette to balance the richness of the dish.
  4. Crunchy Contrast: Accompany the soup with a side of crisp, raw vegetables like celery sticks or cucumber for a refreshing crunch.
  5. Pair with a White Wine: For an elegant touch, pair the French Onion Soup with a glass of dry white wine, enhancing the overall dining experience.

What to Serve with Crock Pot French Onion Soup

Kid-Friendly sides:

  1. Cheesy Stovetop Macaroni: Combine cooked macaroni with a creamy cheese sauce for a kid-friendly comfort food side.
  2. Crispy Veggie Fritters: Grate zucchini and carrots, mix with breadcrumbs and cheese, then pan-fry into tasty fritters. A fun way to sneak in veggies!
  3. Air Fryer Chicken Tenders: Coat chicken strips in a seasoned breadcrumb mixture and Air Fry until golden brown. Serve with a favorite dipping sauce for a crowd-pleasing option.

Family-Friendly Sides:

  1. Roasted Vegetables: Toss a medley of vegetables like carrots, broccoli, and cauliflower with olive oil, garlic, and Parmesan, then roast until tender and flavorful.
  2. Creamy Broccoli Mashed Potatoes: Whip up smooth broccoli mashed potatoes with broccoli, cheese, butter and cream for a classic and comforting side that pairs well with various main dishes.
  3. Buttered Corn on the Cob: Serve sweet corn on the cob brushed with melted butter and a sprinkle of salt—a simple, delicious side loved by both kids and adults.

Date Night Sides:

  1. Truffle Parmesan Risotto: Indulge in a luxurious side dish with creamy truffle-infused Parmesan risotto, offering a sophisticated and rich accompaniment to your main course.
  2. Asparagus with Lemon Zest: Light and elegant, sautéed asparagus with a hint of lemon zest provides a refreshing and vibrant side that complements a variety of date-night meals.
  3. Roasted Brussels Sprouts with Balsamic Glaze: Elevate your dinner with caramelized roasted Brussels sprouts drizzled with a balsamic glaze, offering a delightful balance of sweet and savory flavors.

Storing, freezing, and reheating instructions

Note: For the best results, consider refreshing the soup with a splash of additional broth or water while reheating to maintain its original consistency.

  1. Refrigeration: Allow the soup to cool to room temperature before transferring it to an airtight container. Refrigerate promptly. Consume within 3-4 days to ensure optimal freshness.

Freezing French Onion Soup:

  1. Cool Completely: Cool the soup completely in the refrigerator before freezing.
  2. Airtight Containers: Use freezer-safe containers or resealable bags, leaving some space for expansion.
  3. Labeling: Clearly label the containers with the date for easy tracking.
  4. Freezer Shelf Life: It can be stored in the freezer for up to 3 months.

Reheating French Onion Soup:

  1. Thawing: If frozen, thaw the soup in the refrigerator overnight.
  2. Stovetop Method: Reheat on the stovetop over medium heat, stirring occasionally until heated through.
  3. Microwave Method: Heat in a microwave-safe bowl, stirring at intervals, until thoroughly warmed.
  4. Oven Method: Place in an oven-safe dish, cover with foil, and heat in the oven at a low temperature, checking periodically.

Frequently Asked Questions (FAQs)

Can I use red onions instead of yellow onions in French Onion Soup?

While yellow onions are traditional, red onions can be used for a slightly different flavor. They may add a touch of sweetness and a more vibrant color to the soup. I like to use some of each variety.

What’s a good vegetarian substitute for beef broth in French Onion Soup?

Vegetable broth is an excellent vegetarian substitute, providing a flavorful base. Ensure it’s a high-quality, preferably low-sodium, option for the best results.

Can I make French Onion Soup in advance?

Absolutely! The flavors often improve when allowed to meld. Prepare the soup and refrigerate or freeze. Reheat on the stovetop, adjusting consistency with a bit of broth if needed, before serving.

What can I substitute for cognac in the recipe?

If cognac isn’t available, you can use a dry white wine or omit it entirely. The wine adds depth, but the soup will still be delicious without it. Adjust the quantity based on personal preference.

Drink Pairings

Kid-Friendly:

  1. Fruity Sparkling Lemonade:
    • Create a refreshing blend of lemonade with a splash of sparkling water. Add a few berries or a slice of citrus for a colorful, kid-friendly drink.
  2. Non-Alcoholic Fruit Punch:
    • Mix a fruity concoction using a combination of fruit juices like orange, pineapple, and cranberry. Garnish with slices of fresh fruit for added appeal.
  3. Homemade Smoothies:
    • Blend up a nutritious and tasty smoothie using yogurt, milk, and a mix of favorite fruits like berries, banana, and a touch of honey. A delightful and healthy choice for kids.

Family-Friendly:

  1. Iced Herbal Tea with Citrus:
    • Brew a caffeine-free herbal tea, like chamomile or fruit infusion, and add citrus slices for a refreshing and family-friendly option.
  2. Classic Lemonade:
    • Make a classic lemonade with freshly squeezed lemons, sugar, and water. It’s a timeless and crowd-pleasing choice for all ages.
  3. Sparkling Apple Cider:
    • Provide a festive touch with sparkling apple cider. Garnish with cinnamon sticks or apple slices for a family-friendly beverage suitable for various occasions.

Wine, Cocktail, and Beer Pairings:

Wine Pairings:

  1. Red Bordeaux: Ideal with the rich flavors of Crock Pot French Onion Soup, the tannins in a red Bordeaux cut through the soup’s richness, enhancing the dining experience.
  2. Chardonnay: A buttery Chardonnay complements the creamy texture of the soup, providing a nice balance to the savory onions and cheese.
  3. Dry Riesling: The crisp acidity and slightly sweet notes of a dry Riesling can contrast well with the sweetness of caramelized onions, creating a harmonious pairing.

Cocktail Pairings:

  1. French 75: This classic cocktail made with gin, champagne, lemon juice, and sugar pairs well with Crock Pot French Onion Soup, adding a touch of effervescence and citrusy brightness.
  2. Whiskey Sour: The combination of whiskey, lemon juice, and simple syrup offers a robust flavor that can stand up to the soup’s richness.
  3. Classic Martini: A well-chilled martini, whether gin or vodka-based, provides a clean and sophisticated contrast to the complex flavors of Crock Pot French Onion Soup.

Beer Pairings:

  1. Belgian Dubbel: The caramel and dark fruit notes of a Belgian Dubbel complement the sweetness of caramelized onions, while its effervescence cuts through the richness.
  2. Amber Ale: An amber ale with its maltiness and slight bitterness can provide a nice balance to the savory elements in the soup.
  3. Dry Stout: The roasted malt flavors of a dry stout can enhance the overall experience, especially when paired with the cheesy and toasty elements of the soup.
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This step-by-step recipe makes the best French Onion Soup you've ever eaten. Bring fine French cooking into your own kitchen. Let me show you how easy it is!

Crock Pot French Onion Soup

Ronda Eagle | Kitchen Dreaming
This step-by-step recipe makes the best French Onion Soup you’ve ever eaten. Bring fine French cooking into your own kitchen. Let me show you how easy it is!
5 from 1 vote
Prep Time 10 minutes
Cook Time 50 minutes
Total Time 1 hour
Course Soup
Cuisine French
Servings 6 servings
Calories 376 kcal

Ingredients
  

  • 6 Vidalia onions
  • 3 red onions [See Note 1]
  • 1 tablespoon olive oil
  • 2 tablespoons butter
  • 1/2 to 1 teaspoon salt , more or less to taste
  • 1 teaspoon black pepper
  • 4 cloves garlic , minced
  • 3 tablespoons all-purpose flour
  • 4 tablespoons Cognac [See Note 2]
  • 1/2 to 1 cup white wine [See Note 2]
  • 6 cups low sodium beef cooking stock [See Note 4]
  • 2 thyme sprigs (or 1 teaspoon dried thyme)
  • 2 bay leaves
  • 9 sprigs parsley
  • 1 1/2 cups Gruyere , Emmental (regular) Swiss, Fontina, or Jack cheese, grated or sliced [See Note 5]
  • Artisan bread , like French baguette, croutons, or rusks

Instructions
 

  • In a large skillet, melt the butter and oil over medium-high heat. Add the onions and sauté until softened.
  • Turn the heat down to medium-low and continue to sauté until browned and caramelized (but not burnt), about 30 minutes, stirring every few minutes. (This can be done the night before if needed).
  • Add garlic and sauté for an additional 1-2 minutes. Stir in the flour and cook for an additional 1 minute. Transfer into the crock pot.
  • Deglaze the pan by pouring in the cognac (optional) and dry white wine into the skillet over medium heat. Using a wooden spoon, scrape up any browned bits on the bottom of the pan. Cook off the alcohol in the wine by allowing it to boil for about 2 minutes. Pour into the crock pot.
  • Add the cooking stock, bay leaves, thyme sprigs, and parsley. Cover and cook on low for 6 to 8 hours or 4-6 hours on high.
  • When finished, discard the bay leaves, sprigs of thyme, and parsley.
  • Preheat oven broiler.
  • When ready to serve the soup, place your oven-safe bowls [See Note 6] or crocks on a rimmed baking sheet [paid link]. Ladle the soup into each of them, then top with a baguette slices (or croutons, or rusks) and cheese (I used about 1/4 cup shredded cheese for each). Place on an oven rack about 6 inches from the heat and broil for 2-4 minutes until the cheese is melted and bubbly.
  • Remove and serve immediately.

Notes

  1. You may use all sweet Vidalia onions, but I like the combination of Vidalia and milder red onions. If you prefer not to use red onions, opt for all vidalia onions.
  2. Cognac is traditional to the recipe but may be omitted without substitution. 
  3. Sauvignon Blanc, a dry white wine, may be replaced with any other dry white wine (see below), extra cooking stock, or water.
    • Chardonnay:
      • Chardonnays grown in a cool climate, will have more flavors like citrus, peach, and melon.
      • Chardonnays grown in a warm climate will have more tropical fruit aromas like mango, kiwi, star fruit, and pineapple.
      • Oak-aged Chardonnays are rich, full-bodied and have additional flavors of vanilla, butterscotch, spice, nuts and of course, oak.
    • Pinot Grigio: The primary fruit flavors in Pinot Grigio are lime, lemon, pear, white nectarine and apple.
    • Pinot Gris: Pinot Gris hails from the Alsace region of France is typically rich and often sweet, with rich, spicy tropical fruit aromas.
    • Pinot Blanc: A semi-dry white wine that is often compared to Chardonnay. It is typically crisp and refreshing and, depending on where it’s made. Pinot Blanc can be sweet or have nutty flavors.
    • Sémillon: Sémillon is a golden-skinned grape used to make dry and sweet white wines, mostly in France and Australia. The primary fruit flavors in Sémillon wine are lemon, apple, pear and green papaya.
  4. Beef, Vegetable, or Chicken Stock: Traditionally, beef stock is used as the base of French Onion Soup. However, if you prefer chicken or vegetable those may be easily substituted in the broth.
  5. Cheese choices:
    • Gruyere: A moderate-fat Swiss cheese with a rich, sweet, nutty flavor. It is usually aged for 10 – 12 months and has a golden brown rind and a firm pale yellow interior with well-spaced, medium-sized holes. It’s aged in 100-pound wheels that are later cut into wedges before it heads to market. Gruyere is a product of France as well as several other countries.
    • Emmental Swiss: This is Switzerland’s oldest and important Swiss cheese. Both Switzerland and France make great Emmental cheese with mellow, buttery, and nutty flavor suitable for almost any use. Made from partially skim unpasteurized cow’s milk. The rind is yellow-beige with a pale yellow interior with marble-sized holes.
    • Fontina: This is one of Italy’s great cheeses. It is semi-firm yet creamy. Made from cow’s milk, it is about 45% fat. The rind is dark golden brown with a pale yellow interior and tiny holes. Fontina has a mildly nutty flavor. It melts easily and smoothly and is perfect for almost any use. Fontina is also made in France, Denmark, and the United States.
    • Jack Cheese: A semi-soft cheese with a buttery-ivory color and a mild flavor reminiscent of an American Muenster. Unaged, Jack cheese has high moisture and good melting properties.
  6. No ovenproof bowls? No problem! If you don’t have oven-safe bowls or ramekins for the soup, don’t worry—you can just top your soup with cheese toasts you broiled in the oven. Both methods work great!

Nutrition

Serving: 1servingCalories: 376kcalCarbohydrates: 35gProtein: 14gFat: 17gSaturated Fat: 9gPolyunsaturated Fat: 1gMonounsaturated Fat: 6gTrans Fat: 1gCholesterol: 46mgSodium: 369mgPotassium: 543mgFiber: 4gSugar: 19gVitamin A: 580IUVitamin C: 23mgVitamin D: 1µgVitamin E: 1mgVitamin K: 29µgCalcium: 425mgFolate: 100µgIron: 2mgZinc: 2mg
Tried this recipe?Let us know how it was!

1 thought on “Crock Pot French Onion Soup in just 6 simple steps!”

  1. Seriously, I order this soup everytime I see it on the menu but it can get expensive. This was fatty and I agree broth aside (which was delicious in its own right) but the true flavor of a good French onion soup lived in the cheese. Mozzarella is just not an acceptable cheese it’s too mild. The cheese needs a punch against that broth. Awesome

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