Preparation:

Step 1: Prepare the Filling

1. Cook the Ground Beef: In a large skillet over medium heat, cook the ground beef until browned, breaking it up as it cooks. Drain any excess fat from the skillet.
2. Add Aromatics: Once the beef is cooked, add the finely chopped onion and minced garlic to the skillet. Sauté for about 3-4 minutes until the onion becomes soft and translucent.
3. Season the Beef: Stir in the cumin, paprika, oregano, salt, and pepper, blending the spices well with the meat and onion mixture.
4. Incorporate the Tomato Sauce: Add the tomato sauce to the skillet and stir until everything is evenly combined. Let the mixture simmer for about 5 minutes, allowing the sauce to reduce slightly and the flavors to meld.
5. Add the Cheese: Once the filling has thickened, remove it from the heat and stir in the shredded cheese. Let the mixture cool slightly before using it to fill the empanadas.

Step 2: Make the Dough

1. Mix the Dry Ingredients: In a large mixing bowl, combine the all-purpose flour and salt. Stir well to ensure the salt is evenly distributed.
2. Cut in the Butter: Add the cold, cubed butter to the flour mixture. Using a pastry cutter or your fingers, blend the butter into the flour until the mixture resembles coarse crumbs.
3. Form the Dough: Gradually add the cold water to the flour-butter mixture, stirring until the dough begins to come together. If necessary, add a little more water, 1 tablespoon at a time, until a cohesive dough forms.
4. Chill the Dough: Shape the dough into a ball, wrap it in plastic wrap, and refrigerate it for at least 30 minutes. Chilling the dough helps it firm up, making it easier to work with and resulting in a flakier texture when baked.

Step 3: Assemble the Empanadas

1. Preheat the Oven: Set your oven to 375°F (190°C) and line a baking sheet with parchment paper.
2. Roll out the Dough: On a lightly floured surface, roll the chilled dough out to about 1/8 inch thick. Use a round cutter or a glass with a diameter of about 4-5 inches to cut out dough circles.
3. Fill the Empanadas: Place a spoonful of the beef and cheese filling in the center of each dough circle. Be careful not to overfill them, as this could cause the empanadas to burst open during baking.
4. Seal the Empanadas: Fold each dough circle in half to create a half-moon shape. Press the edges together with your fingers, then use a fork to crimp the edges and ensure a tight seal.
5. Brush with Egg Wash: Beat the egg and brush it lightly over the tops of the empanadas. This will give them a beautiful golden-brown color when baked.

Step 4: Bake the Empanadas

1. Bake the Empanadas: Place the prepared empanadas on the lined baking sheet, spacing them evenly apart. Bake for 20-25 minutes, or until they turn golden brown and crispy.
2. Cool and Serve: Once baked, remove the empanadas from the oven and let them cool slightly before serving.