In
a large skillet, combine beef, garlic, and onions. Cook
and stir over medium heat until browned. Drain fat.
Add
tomato sauce, tomatoes, mushrooms, oregano, basil, salt
and pepper. Bring to a boil, reduce heat and simmer
20 minutes.
Cook
pasta and drain.
In
a 4 quart (or larger) casserole, layer 1/2 of the pasta.
Top with the 1/2 of the meat sauce, 1/2 of the sour
cream, 1/2 of the cheddar cheese. Repeat layers and
top with the mozzarella cheese.
Cover
and bake at 350 degrees F. for 45 minutes. Remove cover
and continue to bake until cheese is melted. Makes 10
servings.