Preheat the oven to 400 °F. Line a baking sheet with tin foil or parchment paper.
In a small bowl, prepare the glaze. combine the barbecue sauce, dijon mustard, and brown sugar together until mixed thoroughly. Set aside for step 7.
In a large bowl, whisk together the milk and egg in a small bowl; add the panko and set aside. this allows the panko to absorb the moisture and keep the meatloaf moist.
By hand, or with a food processor, mince the onion, garlic, carrot, celery, and parsley together. Add this to the bowl with the panko mixture. Add the barbecue sauce, Dijon mustard, Worcestershire sauce, salt, and ground pepper. Stir to combine.
Next, add the ground pork and ground beef to the bowl and mix with your fingertips. Once well combined, form the mixture into 4 mini loaves.
Place on prepared rack and bake for 15 minutes. [See Note 2]
After 15 minutes, remove the pan from the oven and spoon about 1 tablespoon of the glaze onto the top of each meatloaf. Brush the glaze on the loaves after cooking for 15 minutes then continue to cook for an additional 20 minutes or until a meat thermometer reads 160 °F.
Notes
If you prefer, you may choose to use just barbecue sauce as the glaze instead of creating a blended sauce.
If you prefer not to brown the meatloaves before adding the glaze, skip the short bake time and spoon the glaze over the loaves before placing them into the oven.