Preheat your oven to 200°C (390°F) and line a baking tray with parchment paper so the sausage rolls don’t stick and cook evenly from the bottom without burning.
Take a mixing bowl and add the chicken or turkey sausage (remove casing if needed), shredded cheese, well-drained sauerkraut (press out excess liquid with your hands or a paper towel), garlic powder, paprika, black pepper, and olive oil. Mix everything thoroughly using a spoon or your hands until the mixture is fully combined and slightly sticky.
Place the puff pastry sheet on a clean, lightly floured surface and gently roll it out with a rolling pin if it looks too thick. This helps create a more balanced pastry-to-filling ratio and ensures even baking.
Spoon the prepared sausage mixture along one long edge of the pastry, forming a log shape. Keep the layer even and not too thick so the rolls cook properly from inside without staying raw.
Carefully roll the pastry over the filling, keeping it tight but not overly compressed, and seal the edge by pressing it gently. You can lightly brush the edge with water to help it stick better.
Using a sharp knife, slice the rolled log into equal-sized pieces (about 2–3 inches each). Clean cuts help the rolls hold their shape and look more professional after baking.
Arrange each piece on the prepared baking tray, leaving a little space between them so hot air can circulate and the pastry crisps up nicely on all sides.
Crack the egg into a small bowl, beat it well, and brush it evenly over the tops of each roll. This step is key for achieving that golden, shiny, bakery-style finish.
Place the tray in the preheated oven and bake for 20–25 minutes, or until the pastry is puffed, golden brown, and crispy, and the filling is fully cooked inside. Rotate the tray halfway through if your oven heats unevenly.
Remove the rolls from the oven and let them cool for 5–7 minutes before serving. This resting time allows the filling to set slightly and prevents burning your mouth while keeping the texture perfect.