Preheat 350°F oven
9"x9" casserole pan
If calories are not a concern, the 2 Tbsp of oil may be swapped out for 4 Tbsp of butter.
Cream of mushroom soup substitutes well for the milk and mushrooms called for in the recipe. Soup adds more calories and a richer taste.
Spinach, tomatoes, and/or other fresh vegetables may be layered into the cheesy tuna casserole to create a tuna strata.