Preheat your oven to 375°F (190°C) and line a baking sheet with parchment paper.

In a skillet, heat over medium-high, then add the ground beef. Cook until browned and crumbly, about 5-7 minutes.

Add the chopped onion to the skillet and sauté until it becomes translucent, about 3-4 minutes.

Stir in the diced potatoes, peas, dried thyme, Guinness stout, Worcestershire sauce, salt, and pepper. Simmer for about 7-8 minutes until potatoes are tender.

Roll out your pastry dough on a floured surface. Cut out 16 smaller circles (about 5 inches) and 16 larger circles (about 5.5 inches).

Place a spoonful of the beef mixture onto each smaller pastry circle. Brush edges with milk and top with larger circles, crimping edges to seal.

Transfer the hand pies onto the baking sheet. Brush tops with milk and bake for 12-15 minutes until golden brown.

Once baked, cool slightly before serving to set the filling.