This is a delicious filling that is put onto hamburger (or hot dog) rolls and baked in the oven. Fantastic for a cold weekend day when the kids need a good lunch. This recipe came from my mother. It has been one of my favorite recipes for over 30 years.
Preheat oven to 400 degrees F (200 degrees C).
Cook and stir ground beef in a large skillet until well browned, about 10 minutes; drain fat. Place cooked beef in a large bowl. Stir in tomato sauce, onion, black olives, pimentos, mushrooms, Cheddar cheese, chili powder, salt, and black pepper.
Spoon sandwich filling on hamburger bun bottoms, spreading to the edges. Filling should be approximately 1/2" thick in the center of the sandwich.
Bake in the preheated oven until the edges start to bubble, 5-10 minutes. Turn oven to Broil and continue to cook until heated through, about 3 minutes.
Per Serving: 261 calories; protein 15.6g; carbohydrates 16.2g; fat 15.1g; cholesterol 49.5mg; sodium 663.4mg.