In a cast iron skillet over medium heat, brown 1 pound of ground beef for about 5-7 minutes until well-cooked. Add 1 diced onion and 1 teaspoon of thyme, cooking until the onion softens, approximately 3-4 minutes. Pour in 1 cup of Guinness stout and let it simmer uncovered for 15 minutes.

In a large mixing bowl, combine 2 cups of pastry flour and 1 cup of cold, cubed butter. Mix until it resembles coarse crumbs. Gradually add 5-6 tablespoons of cold water until the dough comes together. Wrap in plastic wrap and chill for at least 30 minutes.

Preheat your oven to 350°F (175°C). Roll out the dough to about 1/8-inch thickness. Cut out circles using a 4-inch round cutter and place on a parchment-lined baking sheet. Spoon 1-2 tablespoons of the beef filling onto one half of each circle, fold over and pinch the edges to seal. Brush the tops with an egg wash.

Bake for 18-22 minutes until golden-brown. Rotate the baking sheet halfway through for even browning. Once done, let them cool slightly before serving.