To prepare a tuna casserole microwave style casseroles recipe, first you need to prepare the ingredients for the casserole. First, you'll need the following ingredients: 12 cup shredded cheddar cheese 2 tablespoons mayonnaise 2 teaspoons kosher salt 1 tablespoon melted margarine 1 teaspoon paprika Instructions Preheat the oven to 375 degrees F (190 degrees C) and grease an 8 x8-inch casserole dish with non-stick cooking spray. Place the cheese in the bottom of the dish and sprinkle with the salt and pepper. Bake for 20 minutes or until cheese is bubbly and browned. Remove from oven and let stand for 5 minutes before cutting into squares and serving.