1. Prepare the Filling:

1. Heat butter or oil in a pan over medium heat. Add chopped onions and sauté until soft.
2. Add ground beef and cook until browned, breaking it apart with a spoon.
3. Sprinkle in the flour and stir to coat the meat, cooking for 1 minute.
4. Pour in beef broth, Worcestershire sauce, and tomato paste. Stir until combined.
5. Season with salt, pepper, garlic powder, and thyme.
6. Let simmer for 10-15 minutes until thickened. Remove from heat and let cool.

2. Assemble the Pies:

1. Preheat oven to 375°F (190°C).
2. Roll out puff pastry and cut into circles to fit a muffin tin or small pie tins.
3. Line each tin with pastry, pressing gently to fit.
4. Spoon cooled meat filling into each pie base.
5. Cover with another pastry circle, sealing the edges with a fork or by pinching.
6. Brush the tops with beaten egg for a golden crust.

3. Bake & Serve:

1. Bake for 20-25 minutes, or until the pastry is golden brown and crispy.
2. Let cool slightly before serving.
3. Enjoy with tomato sauce (ketchup) or a side of vegetables!