French Onion Sausage Rolls

1. Prepare the Onion Mixture:
   • In a large skillet, melt the butter over medium heat.
   • Add the chopped onion and cook, stirring frequently, until the onions are soft and caramelized, about 10-15 minutes.
   • Stir in the thyme leaves and cook for an additional minute. Remove from heat and let cool slightly.
2. Prepare the Sausage Filling:
   • In a large bowl, combine the sausage meat with the cooled onion mixture.
   • Add the Dijon mustard, grated cheese, breadcrumbs, and season with salt and pepper. Mix until well combined.
3. Assemble the Sausage Rolls:
   • Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
   • Roll out the puff pastry on a lightly floured surface. Cut it into rectangles, about 3 inches by 6 inches (8 cm by 15 cm).
   • Place a portion of the sausage mixture along one edge of each pastry rectangle.
   • Roll the pastry over the sausage filling to form a log shape, sealing the edges by pressing them together with a fork or your fingers.
   • Place the sausage rolls seam-side down on the prepared baking sheet.
4. Prepare for Baking:
   • Brush each sausage roll with the beaten egg for a golden, shiny finish.
   • If desired, sprinkle the tops with sesame seeds or poppy seeds for extra texture and flavor.
5. Bake:
   • Bake the sausage rolls in the preheated oven for 20-25 minutes, or until they are golden brown and puffed up.
6. Cool and Serve:
   • Allow the sausage rolls to cool slightly before serving. They are delicious either warm or at room temperature.

Enjoy these French Onion Sausage Rolls as a flavorful appetizer, snack, or even as part of a meal!