Servings: Serves 4
Preheat the oven to 350°. Grease a 2-quart casserole dish with olive oil and set aside.
Place a large skillet over medium-high heat. Coat with the 1 tablespoon of oil, and when the oil is hot, add the onions.
Cook and stir until softened, about 3 minutes. Stir in corn and cook 2 minutes longer to incorporate. Stir in the soup, salsa and chili powder (if desired) until well blended.
Add the tuna and cooked pasta, stirring just to coat. Pour into the prepared greased casserole dish. Sprinkle the top evenly with cheese.
Bake for about 25 minutes or until bubbling, remove from oven and serve immediately.