To create the perfect Beef Empanadas, follow these simple steps:

1. Make the Dough: In a large bowl, combine the flour and salt. Add the cubed butter and mix until crumbly. Gradually sprinkle water while mixing until a dough forms. Wrap in plastic wrap and refrigerate for 30 minutes.

2. Prepare the Filling: In a skillet, heat a drizzle of oil over medium heat. Sauté the chopped onion and garlic until translucent.

3. Cook the Beef: Add ground beef to the skillet, breaking it apart. Season with cumin, paprika, chili powder, salt, and pepper. Cook until browned. Stir in green olives and diced potatoes if using. Let cool.

4. Roll Out the Dough: On a floured surface, roll out the dough until about 1/8 inch thick. Use a round cutter to cut out circles (about 4-5 inches in diameter).

5. Fill the Empanadas: Place about 1 tablespoon of the beef filling in the center of each dough circle. Fold the dough over and crimp the edges with a fork to seal.

6. Prepare for Baking: Preheat the oven to 400°F (200°C). Place the empanadas on a baking sheet lined with parchment paper.

7. Egg Wash: Beat the egg and brush it over the tops of the empanadas for a golden finish.

8. Bake: Bake in the preheated oven for 25-30 minutes, until golden brown.

9. Cool and Serve: Remove from the oven and allow to cool for a few minutes before serving.

These steps will guide you in creating incredible Beef Empanadas that will wow your family and friends.