Created by KittenCal on October 31, 2011
Step 1: Set oven to 350 degrees F, then spray a 13 x 9-inch baking dish with cooking spray.
Step 2: In a large bowl combine cooked pasta with onion and tuna.
Step 3: In a saucepan heat the soups with milk until smooth; stir in mushrooms, mayonnaise, Mrs. Dash seasoning, garlic powder and black pepper; stir until combined, then transfer to the bowl; toss to combine with pasta and tuna.
Step 4: Transfer to baking dish, then bake for 30 minutes.
Step 5: Remove from oven and sprinkle 1 cup shredded cheese over then return to oven for 2-4 minutes to melt cheese.