Tetrazzini

Directions

1. 1
   Mix the cheeses and sour cream together in a large bowl; set aside.
2. 2
   Cook spaghetti.
3. 3
   Brown beef and fry onions together.
4. 4
   Add spaghetti sauce and mushrooms; simmer for about 7 minutes.
5. 5
   Drain the spaghetti and mix it with cheese mixture.
6. 6
   Spread it in a 13 x 9 x 2-inch glass baking dish.
7. 7
   Pour sauce over it.
8. 8
   Bake at 350° for 30 minutes.