In a mixing bowl, combine the sifted flour and salt. Mix well to ensure even distribution.

Add the cold, cubed butter to the flour mixture. Use a pastry cutter or your fingers to blend until the mixture resembles coarse crumbs.

Gradually add cold water, one tablespoon at a time, mixing until the dough comes together. Avoid overworking the dough to keep it flaky.

Form the dough into a ball, wrap it in plastic wrap, and refrigerate for at least 30 minutes.

In a skillet, heat the olive oil over medium heat. Add the diced onion and sauté until translucent, about 5 minutes.

Add the minced garlic, cumin, paprika, and black pepper. Cook for an additional minute until fragrant.

Add the ground beef to the skillet. Cook, breaking it apart with a spatula, until browned and cooked through, about 7-10 minutes.

Remove from heat and stir in the chopped hard-boiled egg, green olives, and parsley. Allow the filling to cool.

Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.

On a floured surface, roll out the chilled dough to about ⅛ inch thick. Use a round cutter (about 4-5 inches in diameter) to cut out circles.

Place a tablespoon of the beef filling in the center of each dough circle. Be careful not to overfill.

Moisten the edges of the dough with water, fold the dough over the filling to create a half-moon shape, and press the edges to seal. Use a fork to crimp the edges for a decorative touch.

Place the empanadas on the prepared baking sheet. Brush the tops with the beaten egg for a golden finish.

Bake in the preheated oven for 20-25 minutes, or until golden brown.

Remove from the oven and let cool slightly before serving. Enjoy warm!