Cheesy Pasta & Beef Casserole

Cook & drain:
1 lb. lean hamburger
1 chopped onion
Cook until almost done:
4 c. uncooked penne pasta

Combine and stir w/ above ingredients:
1 c. grated cheddar
1 c. grated mozzarella
1 c. tomato sauce

Put into crockpot and top with 3 more T. of tomato sauce and grated parmesan cheese.

Cook low 3-5 hours or 1.5-2.5 on high.