FOR THE DOUGH:
3 cups all-purpose flour
1 teaspoon salt
1/2 cup (1 stick) unsalted butter, chilled
1/2 cup cold water
2 egg yolks, divided
FOR THE FILLING:
1 lb ground beef (can also use 1 lb leftover roast, chopped)
1 lb waxy potatoes, such as red or Yukon gold, diced
2 carrots, peeled and diced
1 small onion, diced
2 tablespoons Worcestershire sauce
2 cloves garlic, minced
1/2 teaspoon dried rosemary
1/2 teaspoon dried thyme
Kosher salt and freshly ground black pepper, to taste
In a large mixing bowl, whisk together the flour and salt.
Cut butter into small pieces and using two forks, a pastry blender, or your fingers, work it into the flour until it becomes a crumbly mixture.
Mix together water and one of the egg yolks, then add to the flour mixture. Mix until all flour is incorporated, then turn out onto a clean surface and knead until the mixture comes together completely.
Wrap in plastic wrap and chill dough at least 30 minutes.
When ready to bake preheat oven to 400°F and line a baking sheet with parchment paper.
To make the filling:
In a large skillet over medium-high heat, season the ground beef with salt and pepper and brown until no longer pink. Remove meat to a bowl and set aside.
To the same skillet, add potatoes, onion, and celery and cook until mostly soft, 6-8 minutes. If there isn’t enough fat leftover from the beef, add olive oil or butter to the skillet before adding vegetables.
Add garlic, rosemary, and thyme and cook until fragrant, about 1 minute. Add Worcestershire sauce and cook 1 minute more.
Add vegetable mixture to bowl with beef and stir to combine. Season to taste with salt and pepper and set aside to cool.
Once filling has cooled to room temperature, you can assemble the pasties.
Flour a clean surface and divide dough into 6 portions. Roll each ball out into a 3/8-inch thick circle, trimming edges to neaten, if needed.
Wet the edges of your dough with some water, then spoon cooled beef mixture over a little less than half of the dough, leaving a 1/2-inch border.
Fold dough over the filling and seal edges by crimping or using a fork to press the dough layers together.
Transfer pasty to prepared baking sheet and cut three small slits in the top as a vent. Repeat with remaining pasties.
Whisk together remaining egg yolk with 2 tablespoons water and brush over the top of each pasty. Bake until golden brown, 30-40 minutes.
Note: If you plan to freeze some of the pasties, skip the egg wash and bake for only 20 minutes. Later, brush frozen pasty with egg wash, then bake at 400°F for 20 more minutes.