Heat a large saute pan on medium heart. Add 1 tablespoon of oil and the butter. Once the butter is melted, add the sliced peppers and onions. Season with salt and pepper to taste, and cook until tender but not browned, about 5-6 minutes.
Add the sliced beef into the pan, season with salt, pepper and garlic powder. Saute the beef with the peppers and onions until the beef is no longer pink.
Add the sliced cheese on top of the beef & veggies and stir until the cheese melts and coats the mixture. Set aside to cool
Add 2-3 tablespoons of the cheesesteak mixture into the center of each empanada disc. Make sure to leave a border so you can seal it.
Close up the empanada with a fork. Press down hard on both sides, you don't want this luscious filling oozing out during the frying process.
Serve with ketchup, or my mayoketchup dipping sauce.
Freeze uncooked empanadas by wrapping them individually in plastic wrap or wax paper, and stacking them into a freezer bag. Defrost overnight in the fridge before frying.