If necessary, cook the sausages through and set aside to cool.
Preheat the oven to 425°F and lightly grease a baking sheet.
Prepare the dijonaise by placing all the dijonaise ingredients in a bowl and whisking until thoroughly combined. Place in a small serving dish and set aside.
Onto a clean work surface, scatter a tablespoon or two of flour. Roll out 1 sheet of pastry to flatten it.
Cut the sheet of puff pastry in half lengthwise (along the middle of the long side), roll out the pastry slightly if needed to fit the sausage. Lay a cooled sausage onto the pastry dough roll it to cover the sausage completely. It's okay to leave the ends uncovered but is also okay to wrap them completely, if you prefer. Sometimes, I add a small bit of the dijonaise inside the pastry dough but you can leave that for the side in case your guests don't care for it.
Working with the second piece of dough the same way you did with the first piece wrap both sausages.
Using a fork, press the pastry edges to seal. If needed, dip your finger in some water to wet the edge of the dough to make it stick better during the sealing process.
Brush the tops of the pastry with the egg wash. This encourages browning of the dough.
Slice the sausages into your desired thickness and lay them on the try an inch or two apart.
Bake until the pastry dough is golden brown and has puffed up slightly, about 20 minutes.
Serve hot or at room temperature.
This recipe can easily be doubled with two (1 lb) packages of Andouille Sausage links to every one package (two sheets) of frozen puff pastry.Nutrition is calculated based on the recipe as written. Additions, omissions, or substitutions will change the calculated values shown. The addition, omission, or substitution of ingredients will alter the nutritional information shown. Nutrition percentages are based on a 2000-calorie diet. The FDA recommends 80 micrograms of vitamin K.