Step 1 — Preheat Oven : Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper.

Step 2 — Prepare the Filling : In a mixing bowl, combine sausage meat, shredded cheddar, parmesan (if using), garlic powder, herbs, and black pepper. Mix well until evenly combined.

Step 3 — Roll Out the Puff Pastry : Lightly flour your work surface. Roll the thawed puff pastry sheet into a rectangle (about 10×12 inches). Spread a thin layer of Dijon mustard across the pastry if desired.

Step 4 — Add Filling and Shape : Spoon the sausage mixture in a long line along one edge of the pastry. Roll the pastry tightly over the filling, sealing the edge with a bit of beaten egg. Cut into rolls about 1½–2 inches thick.

Step 5 — Egg Wash : Place rolls seam-side down on the lined baking sheet. Whisk together the egg and water, then brush the tops with the egg wash. Sprinkle with sesame or poppy seeds if desired.

Step 6 — Bake : Bake in the preheated oven for 25–30 minutes, or until golden brown and puffed. The sausage should be cooked through and the pastry flaky and crisp.

Step 7 — Cool Slightly and Serve : Let the rolls cool for 5 minutes before serving — this allows the cheese to set slightly.