Prepare the Sausage Filling:

1. Cook the Onion: In a skillet, heat olive oil over medium heat. Add the chopped onion and cook for 3-4 minutes until softened and translucent.
2. Combine Sausage and Herbs: In a large bowl, combine the sausage meat, cooked onions, chopped sage, thyme, and salt and pepper to taste. If using, stir in cranberries or diced apple for added sweetness.
3. Add Cheese (Optional): For an extra rich flavor, stir in some grated cheese to the sausage mixture. This will melt into the filling during baking, making the rolls even more delicious.

Assemble the Sausage Rolls:

4. Preheat the Oven: Preheat your oven to 400°F (200°C).
5. Roll Out the Pastry: On a lightly floured surface, roll out the puff pastry to a rectangle large enough to fit the sausage filling. If using two smaller sheets, roll them out separately.
6. Shape the Sausage Rolls: Place the sausage mixture in a long strip along the center of the pastry. Roll the pastry over the filling to encase it, pinching the edges to seal. Cut into individual rolls, about 2 inches wide.
7. Prepare for Baking: Place the rolls on a baking sheet lined with parchment paper. Use a pastry brush to coat the tops of the rolls with a beaten egg for a golden, glossy finish.

Bake and Serve:

8. Bake the Rolls: Place the sausage rolls in the preheated oven and bake for 25-30 minutes or until golden brown and puffed up.
9. Serve Warm: Allow the rolls to cool for a few minutes before serving. Serve them warm with a side of cranberry sauce or a tangy mustard dip.