8 ounces lasagna noodles
2 large onions, diced
8 ounces sharp cheddar cheese, grated (2 cups)
4 cups mashed potatoes, made fresh or leftover
4 tablespoons butter
Salt and pepper to taste
Cook noodles according to package and set aside. Brown the butter in a medium skillet, being careful not to burn. Add the onions and sauté until softened and lightly browned. Combine the cheese and mashed potatoes. Butter or spray a 13x9x2-inch baking dish. Line the bottom with a layer of noodles. Add a layer of potato and cheese mixture then spread with a portion of the onions. Continue to layer the ingredients ending with a layer of noodles topped with onions. Bake at 350° F for 15 to 20 minutes, or until bubbly and lightly browned. Tent with foil if the top browns too quickly.
Notes: Browning the butter adds a lot of flavor to the casserole. If you prefer, it could just be melted. If making freshly mashed potatoes, use about 8 large potatoes. If you don't have enough leftover potatoes, add some fresh or make some from instant potatoes. The recipe can easily be halved.