Step 1

Preheat the oven to 350 F. Prepare a 5x9-inch baking pan and spray it with some cooking oil.

Step 2

In a bowl, mix together all of the ingredients: drained tuna, chopped bell pepper, chopped onion, mayonnaise, shredded mozzarella, cottage cheese, pepper flakes, and garlic salt.

Step 3

Bake for 20-25 minutes or until the cheese has melted and the top of the casserole turned golden brown.