Make the Dough:
Combine dry ingredients:
In a large mixing bowl, whisk together the flour and salt. Add the cubed butter and mix until the mixture resembles coarse crumbs.
Incorporate wet ingredients:
Beat the egg, water, and vinegar together in a small bowl. Gradually add this mixture to the flour, stirring until a dough forms.
Chill the dough:
Knead the dough gently into a ball, wrap in plastic wrap, and refrigerate for at least 30 minutes.
Prepare the Filling:
Cook the aromatics:
Heat olive oil in a skillet over medium heat. Add the onions and garlic, cooking until softened, about 2–3 minutes.
Cook the beef:
Add the ground beef and cook, breaking it up with a spoon, until browned and cooked through. Drain any excess grease.
Add the flavors:
Stir in the diced bell pepper, tomato sauce, cumin, paprika, chili powder (if using), salt, and pepper. Simmer for 5–7 minutes until thickened. Stir in olives and parsley. Let the filling cool completely.
Assemble the Empanadas:
Roll out the dough:
On a lightly floured surface, roll out the dough to about 1/8-inch thickness. Cut into circles using a pastry cutter.
Fill and seal:
Place a spoonful of the beef filling in the center of each circle. Fold the dough over to form a half-moon shape, and press the edges together. Use a fork to crimp the edges.
Brush with egg wash:
Place the empanadas on a parchment-lined baking sheet and brush with the egg wash.
Cook the Empanadas:
To bake:
Preheat the oven to 375°F (190°C). Bake for 20–25 minutes or until golden brown.
To fry:
Heat oil in a deep skillet to 350°F (175°C). Fry empanadas in batches for 3–4 minutes per side, or until golden and crispy. Drain on paper towels.