This is a family favorite. I call it "Wisconsin Lasagna" because it uses Colby cheese (which was created in Colby, WI) instead of the typical mozzarella -- and also because I live in America's Dairyland -- home of the best cheese in the world!
In a large saucepan, brown hamburger with onion and salt & pepper. Drain grease. Add tomato sauce and oregano; bring to a boil. Reduce heat; cover and simmer for 30 minutes, stirring occasionally.
In a 9"x13" baking dish, layer ingredients in this order: meat sauce, shredded colby cheese, and 3 cooked noodles. Continue layering, ending with a layer of meat sauce. Sprinkle liberally with parmesan cheese.
Cover tightly with foil and bake at 350 degrees for 45 minutes. Remove foil and bake an additional 15 minutes. Remove from oven and allow to sit for 10 minutes before cutting.