# What You'll Need:
→ Caramelized Onions
01 - 2 tablespoons olive oil
02 - 2 large yellow onions, thinly sliced
03 - 1 teaspoon granulated sugar
04 - 1/2 teaspoon kosher salt
05 - 1 tablespoon balsamic vinegar
→ Sausage Filling
06 - 1 pound pork sausage meat or sausage links with casings removed
07 - 1 teaspoon dried thyme
08 - 1 teaspoon Dijon mustard
09 - 1/4 teaspoon freshly ground black pepper
10 - 1/4 teaspoon kosher salt
11 - Caramelized onions prepared above, cooled
→ Assembly
12 - 1 sheet puff pastry, about 9 ounces, thawed if frozen
13 - 1 large egg, beaten
14 - 1 tablespoon sesame seeds or poppy seeds, optional
# Steps to Follow:
01 - Heat olive oil in a large skillet over medium heat. Add sliced onions, sugar, and salt. Cook, stirring regularly, for 15 to 20 minutes until onions reach a deep golden color and soft texture. Stir in balsamic vinegar and continue cooking for 2 minutes. Allow to cool completely.
02 - Preheat oven to 400°F. Line a baking sheet with parchment paper.
03 - In a large mixing bowl, combine the sausage meat, dried thyme, Dijon mustard, ground black pepper, salt, and cooled caramelized onions. Mix until ingredients are evenly blended.
04 - Roll out puff pastry on a lightly floured surface into a 12 x 10 inch rectangle. Cut lengthwise into two equal strips.
05 - Divide the sausage filling in half. Shape each half into a long log down the center of each pastry strip.
06 - Brush one long edge of each pastry strip with beaten egg. Fold pastry over sausage filling to enclose, pressing edges to seal. Place each roll seam-side down.
07 - Cut each filled pastry log into 8 equal pieces. Transfer to the prepared baking sheet, spacing evenly. Brush tops with remaining egg wash, and sprinkle with seeds if desired.
08 - Bake for 20 to 22 minutes, until pastry is puffed and golden brown and filling is fully cooked.
09 - Allow sausage rolls to cool briefly before serving warm or at room temperature.
