Heat 2 tablespoons butter in a large skillet over medium heat. Add diced onion and red bell pepper, sauté 5-7 minutes until softened but not browned.
1 whole red bell pepper, 1 medium onion, 2 tbsp butter or oil
Add 1 pound ground beef, break into small pieces with a wooden spoon. Cook 6-8 minutes until no longer pink, then drain excess fat into a bowl and discard.
1 lb ground beef
Stir in smoked paprika, cumin, salt, pepper, chopped olives, and beef broth. Simmer 3-4 minutes until liquid thickens and coats the beef, then remove from heat and fold in chopped hard-boiled eggs.
1 tsp smoked paprika, 1 tsp ground cumin, 0.5 tsp salt, 0.25 tsp black pepper, 0.25 cup green olives, 0.33 cup beef broth, 2 whole hard-boiled eggs
Transfer filling to a shallow dish and refrigerate 20 minutes before assembling.
Place 2-3 tablespoons chilled filling on one half of each empanada disc, leaving a 1-inch border, then fold dough over and press edges firmly with a fork.
10 pieces empanada dough discs
Arrange empanadas on a parchment-lined baking sheet 1 inch apart. Brush with beaten egg if using, then bake at 375°F for 22-25 minutes until golden brown and slightly puffed.
10 pieces empanada dough discs, 1 whole egg