Personally I can't stand this, but my mother loved it and often made it for Sunday dinner.
1 10 ounce can or frozen package of French cut green beans
1 can condensed cream of mushroom soup
8 ox container of sour cream
1/4 cup finely chopped onion
1 clove minced garlic
salt and pepper to taste
1 can of French fried onions or chow mein noodles for topping
Preheat oven to 350 degrees. Mix everthing except the topping together in a 1 1/2 quart casserole dish. Bake for 25 minutes then top with French fried onions or lightly crushed chow mein noodles and bake for 5 more minutes to crisp the topper.