For the Dough:
450 grams AP flour
2 teaspoons baking powder
1 teaspoon salt
125 grams cold, unsalted butter, cut into small chunks
2 egg yolks
½ cup cold water, plus extra as needed
For the Filling:
3 tablespoons butter
½ pound potatoes, peeled, diced into 1/3-inch cubes
1 small turnip, peeled, cut into 1/3-inch cubes
150 grams (1/3 LB) diced onion, diced small
1 pound skirt or sirloin steak, diced
1 teaspoon salt
1 teaspoon black pepper
1 tablespoon cream
Add all dry ingredients into the bowl of a food processor. Pulse a few times to combine. Add in the butter and process until you get the texture of bread crumbs. Add the egg yolks and process to combine. While the food processor is running, slowly drizzle in the water. As soon as a dough forms, stop adding water. If the dough feels dry, add more water a tablespoon at a time. Wrap dough in plastic wrap and place in the refrigerator for an hour to chill.
While the pastry chills prepare the filling. Heat the butter in a large nonstick pan until foaming. Add the onion and cook until translucent. Add the potatoes and cook for 8-10 minutes until they are beginning to soften. Remove from the heat and allow to cool completely. Toss with remaining filling ingredients.
After an hour remove you pastry from the refrigerator and preheat your oven to 350˚F. Roll out the pastry on a lightly floured surface until it’s just under ¼-inch thick. Cut 8-inch circles into the dough using a plate as a template. Dough should yield about 6 pasties (you may need to reroll a couple of times).
Sprinkle baking sheets with flour to keep the pasties from sticking.
Place a heaping spoonful of filling on one side of the dough circle, leaving at least an inch of dough along the border. Brush the edges with a little egg wash. Fold the pastry over until the edges meet and you have a semicircle. Using your fingers, crimp the dough all around the edge, sealing well as you crimp. Transfer pastry to a baking tray and pierce the top using a sharp knife to make two little holes to let out the steam. Brush egg wash over the top of the pasties and bake for 45-50 minutes until golden brown. Let cool for at least 10 minutes before eating.