Preheat your oven to 400°F (200°C).

In a medium skillet, heat a splash of olive oil over medium heat. Add the finely diced onion and minced garlic, sautéing for about 5-7 minutes until they become translucent and fragrant.

Once the onion and garlic are ready, transfer them to a mixing bowl. Add the sausage meat, dried sage, dried thyme, ground black pepper, and salt. Combine thoroughly.

Lightly flour your countertop and roll out the thawed puff pastry to a thickness of about 1/8 inch. Cut the pastry into rectangles approximately 4 inches wide and 6 inches long.

Place a generous portion of the sausage mixture onto the center of each pastry rectangle. Fold the pastry over the filling and seal the edges using a fork.

Gently slice small slits on top of each sausage roll. Brush each roll with the beaten egg.

Bake in the preheated oven for about 20-25 minutes until golden brown.

Let the Christmas Sausage Rolls cool on the tray for a few minutes before serving warm.