Preheat your oven to 375°F (190°C).
Heat the olive oil in a skillet over medium heat and add the chopped onion and garlic. Cook until they are soft and translucent, about 5 minutes.
Add the pork sausage to the skillet and break it up with a spoon. Cook until well browned. Stir in the thyme, sage, salt, and pepper, then remove from heat and let cool slightly.
Roll out the puff pastry on a lightly floured surface. Cut into rectangles (about 5×3 inches each).
Divide the sausage mixture evenly among the pastry rectangles, placing a small amount on one end of each rectangle.
Roll the pastry over the sausage, tucking in the ends, and seal with a bit of beaten egg.
Place the rolls seam side down on a baking sheet lined with parchment paper.
Brush the tops of the rolls with the remaining beaten egg for a golden finish.
Bake in the preheated oven for 25-30 minutes, or until they are puffed and golden brown.
Let them cool slightly before serving.
