How to Make It
Heat oven to 350° F. In a large bowl, combine the beef, potatoes, onions, 1 teaspoon salt, and ¼ teaspoon pepper.
Place the flour, butter, and 1 teaspoon salt in a large bowl. With a pastry blender or 2 knives, cut in the butter, working until the mixture resembles coarse meal, with a few pea-size lumps remaining. Add 2⁄3 cup ice water; mix with a fork and work with your hands until a dough comes together. If the dough is still crumbly, add more ice water, 1 tablespoon at a time (up to 4 more tablespoons). Do not overwork. Shape the dough into 4 small disks and let rest for 10 minutes.
On a lightly floured surface, roll each disk into a 10-inch circle.
Divide the beef mixture among the circles of dough, shaping the meat into a small loaf. Gather and pull up the sides of the dough around the filling, pressing the edges together to form a seam on top. Using your fingers, crimp the seam. Transfer the pasties to a parchment-lined baking sheet. Bake until golden brown, 1¼ to 1½ hours.