Prepare the Beef Filling : Heat a skillet over medium heat and add a small amount of oil. Sauté onion, garlic, and red bell pepper until softened, about 3–4 minutes. Add ground beef, breaking it apart with a spatula. Cook until browned and fully cooked. Stir in smoked paprika, cumin, cayenne (if using), salt, and pepper. Remove from heat, mix in chopped parsley and olives. Let the mixture cool slightly.
Prepare Chimichurri Sauce : In a bowl, combine parsley, cilantro (if using), garlic, red wine vinegar, red pepper flakes, olive oil, salt, and pepper. Mix well and let it sit for at least 15 minutes to allow flavors to meld.
Assemble the Empanadas : Preheat oven to 400°F (200°C). Roll out empanada dough or puff pastry and cut into circles (about 4–5 inches in diameter). Place a tablespoon of beef filling in the center of each circle. Fold the dough over the filling to form a half-moon shape. Press the edges with a fork to seal. Brush the tops with beaten egg.
Bake the Empanadas : Place empanadas on a parchment-lined baking sheet. Bake for 20–25 minutes or until golden brown and crispy.
Serve : Serve warm with chimichurri sauce on the side for dipping.