Lazy Perogie Casserole

This is very rich. Excellent with smokies from the BBQ.

9 to 15 lasagna noodles
2 cups cottage cheese
1 egg
1/4 tsp onion salt
1 cup grated cheddar cheese
2 cups mashed potatoes
1/4 tsp salt
1/4 tsp onion salt
1/8 tsp pepper
1 cup butter
1 cup chopped onions

Cook the noodles and line the bottom of a 9x13 inch pan with 1/3 of them. Mix together cottage cheese, egg and 1/4 tsp onion salt. Spoon over noodles, cover with another layer of noodles. Mix the cheddar cheese, potatoes, onion salt, salt and pepper together. Spoon over noodles, and cover with a final layer of noodles. Melt butter and saute onions until clear. Pour over casserole. Cover. Bake 30 minutes at 350 degrees F. Let stand 10 minutes. Serve with sour cream.