- 8 medium onions, thinly sliced
 - 1 cup crushed plain potato chips
 - 2 cups shredded Cheddar cheese
 - 2 (10.75 ounce) cans cream of mushroom soup
 - 1/2 cup milk
 - 1/8 teaspoon cayenne pepper (optional)
 
- Preheat the oven to 350 degrees F (175 degrees C). Butter a 9×13 inch baking dish.
 - Arrange layers of onions, potato chips and shredded cheese in the prepared baking dish. Mix together the cream of mushroom soup and milk; pour over the casserole. Sprinkle cayenne pepper over the top.
 - Bake for 1 hour in the preheated oven, until browned and bubbly.