In a mixing bowl, combine the flour and salt.

Add the chilled butter and mix with fingers until it resembles coarse crumbs.

Gradually add cold water, mixing until the dough comes together.

Knead the dough briefly, then wrap it in plastic wrap and refrigerate for at least 30 minutes.

In a skillet over medium heat, sauté the onion and bell pepper until soft.

Add the cooked meat, cumin, and garlic powder, and cook until heated through.

Once chilled, roll out the dough on a floured surface to about 1/8 inch thick.

Cut the dough into circles using a sharp knife or pastry cutter.

Place a spoonful of filling in the center of each dough circle.

Fold the dough over the filling and crimp the edges with a fork to seal.

Brush the tops with the beaten egg and bake at 375°F (190°C) for 25 minutes, or until golden brown.