Make the pastry:

1. In a large bowl, mix together the flour, sugar, salt, and baking powder.
2. Add the cubed butter and rub it into the flour mixture until you get a crumbly texture.
3. Beat the eggs with cold water and add it to the flour mixture. Mix until dough is formed.
4. Cover the dough and refrigerate for 30 minutes.

Make the filling:

1. Heat oil in a large pan over medium heat. Add the onion and sauté for 5-6 minutes.
2. Add the diced carrots and potatoes and cook for 3-4 minutes.
3. Add the ground beef, breaking it apart, and cook for 4-5 minutes.
4. Season with salt, pepper, thyme, and flour. Mix well.
5. Add water or beef broth and stir until the mixture thickens. Set aside.

Assemble the pies:

1. Divide the dough into 4 pieces and roll each into a 1/8-inch thickness.
2. Cut out round shapes with your desired size.
3. Place about 1-2 tablespoons of the meat mixture in the center of each dough circle.
4. Fold the dough over and seal the edges with your fingers or a fork. Poke the pies with a fork to create a steam outlet.
5. Brush the pies with the beaten egg for a golden finish.

Bake:

1. Preheat the oven to 375°F (190°C).
2. Place the meat pies on a baking sheet and bake for 25-30 minutes or until golden brown.
3. Allow the pies to cool slightly before serving.