Creating Christmas Sausage Rolls is straightforward when you follow these steps:

1. Preheat Oven: Preheat your oven to 400°F (200°C). Line a baking tray with parchment paper.
2. Cook Onions: In a frying pan, sauté the chopped onion and garlic over medium heat until soft and translucent, about 3-4 minutes. Set aside to cool.
3. Mix Sausage Filling: In a mixing bowl, combine the sausage meat, cooked onions, garlic, thyme, sage, salt, pepper, and Worcestershire sauce. Mix until well combined.
4. Prepare Puff Pastry: On a lightly floured surface, roll out the puff pastry sheet into a rectangle about 1/8-inch thick.
5. Form Rolls: Cut the pastry into long rectangles, about 4-5 inches wide. Place a spoonful of the sausage mixture along one side of each rectangle.
6. Roll: Fold the pastry over the filling and press to seal, ensuring the edges are well sealed to prevent spilling.
7. Egg Wash: Place the rolls seam side down on the prepared baking tray. Brush the tops with beaten egg and sprinkle with sesame or poppy seeds if desired.
8. Bake: Bake in the preheated oven for 25-30 minutes or until golden brown and puffed up.
9. Cool: Once baked, remove from the oven and allow to cool slightly before serving.

Following these clear instructions will make preparing your Christmas Sausage Rolls an enjoyable experience!