Argentinian Beef Empanadas

Ingredients

• 3 cups all-purpose flour
• ¼ teaspoon salt
• ¾ cup (6 ounces) unsalted butter, chilled and cut into ½-inch cubes
• 1 large egg
• ¼ to ½ cup water, as needed
• 3 tablespoons olive oil
• 2 medium onions, finely chopped
• 1 green bell pepper, seeds removed and finely chopped
• 2 pounds ground beef
• 2 tablespoons ground cumin
• 1 tablespoon smoked sweet paprika
• 2 teaspoons dried oregano
• 1 tablespoon chili powder
• ½ teaspoon garlic powder
• ½ teaspoon salt
• ¼ teaspoon ground black pepper
• 1 large tomato, seeded and chopped
• 3 hard-boiled eggs, peeled and sliced
• ½ cup pitted green olives (Picholine or Spanish preferred), cut in half lengthwise
• 2 large egg whites, for sealing the empanadas (save the egg yolks if you prefer baking over frying)
• 2 large egg yolks
• 2 tablespoons water
• 1 quart vegetable oil