Preheat the oven to 400°F (200°C) and line a baking sheet with parchment paper.

In a mixing bowl, combine all-purpose flour and salt. Cut in cold unsalted butter until it resembles coarse crumbs. Slowly add cold water and mix until a dough forms. Wrap in plastic wrap and chill for 15-20 minutes.

In a large bowl, mix together ground beef or lamb, diced potatoes, diced carrots, chopped onion, salt, black pepper, and thyme until well combined. Adjust seasonings as needed.

Once chilled, divide the dough into six equal parts and roll each into a 6-inch circle on a lightly floured surface.

Place a generous spoonful of filling on one half of each dough circle, fold, and crimp the edges with a fork to seal.

Brush the tops of the pasties with beaten egg and bake for 35-40 minutes until golden brown.