In a mixing bowl, combine the sifted flour and salt. This helps to evenly distribute the salt throughout the dough.

Add the cold, cubed butter to the flour mixture. Use a pastry cutter or your fingers to work the butter into the flour until the mixture resembles coarse crumbs.

Gradually add the cold water, one tablespoon at a time, mixing until the dough comes together. Avoid overmixing to keep the crust tender.

Wrap the dough in plastic wrap and refrigerate for at least 15 minutes. This resting period allows the gluten to relax, making it easier to roll out.

In a skillet over medium heat, cook the chopped onion and minced garlic until softened, about 3-4 minutes.

Add the ground beef (or turkey) to the skillet. Cook until browned, breaking it apart with a spatula, about 5-7 minutes.

Stir in the thawed mixed vegetables, Worcestershire sauce, thyme, black pepper, and salt. Cook for an additional 2-3 minutes until heated through.

Remove from heat and let the filling cool slightly while you prepare the dough.

Preheat your oven to 400°F (200°C). Grease a muffin tin with cooking spray or butter.

On a floured surface, roll out the chilled dough to about 1/8-inch thickness. Use a round cutter (about 4 inches in diameter) to cut out circles.

Press each dough circle into the muffin tin cups, ensuring they cover the bottom and sides.

Fill each dough-lined cup with the meat filling, being careful not to overfill.

Using the remaining dough, cut out smaller circles or strips to create tops for the pies. Place them over the filling and seal the edges by pressing with a fork.

Brush the tops with the beaten egg to give them a golden color when baked.

Bake in the preheated oven for 20-25 minutes, or until the crust is golden brown and the filling is bubbling.

Remove from the oven and let them cool in the tin for 5 minutes before transferring to a wire rack.

Serve warm or at room temperature. Enjoy your delicious muffin tin meat pies!