Cook noodles as directed on package. Line 9x13-inch pan with one of layer noodles. Mix cottage cheese, egg and onion salt in bowl, and spread over noodles. Cover with another layer of noodles. Spread fried farmers sausage over noodles. Cover with layer of noodles. Mix mashed potatoes and cheese and spread over layer of noodles. Melt butter in frying pan, sauté onions slowly until clear and soft. Pour over casserole. Cover and bake for 45 minutes in 350 ºF oven. Let stand 10 minutes to cool and serve.
Great with sour cream, rhubarb sauce or blueberry syrup.