Preparation Steps

• Preheat oven to 375°F (190°C). Grease a 9x13 inch baking dish.
• In a large skillet over medium-high heat, brown the ground beef. Drain off any excess grease.
• Add the sliced onion and bell pepper to the skillet with the ground beef. Cook until softened, about 5-7 minutes.
• Stir in the beef broth, Worcestershire sauce, garlic powder, salt, and pepper. Bring to a simmer and cook for 2-3 minutes, allowing the flavors to meld.
• If using sliced steak-ums, add them to the skillet and cook for 2-3 minutes, or until just cooked through. If using thinly sliced ribeye, add it and cook until browned.
• In a small bowl, mix together the mayonnaise and both shredded cheeses.
• Spread the meat and vegetable mixture evenly into the prepared baking dish.
• Top the mixture with the cheese and mayonnaise mixture, spreading it evenly over the top.
• Bake in the preheated oven for 20-25 minutes, or until the cheese is melted and bubbly and the casserole is heated through.
• Let stand for a few minutes before serving.