Spinach and Artichoke Casserole

1 (10 oz.) pkgs. Frozen chopped spinach

½ c. finely chopped onion

1 stick butter

1 (1 lb.) can artichokes, chopped

1 pint sour cream

½ c. grated parmesan cheese

Salt and pepper

Cook spinach as directed on box; drain. Sauté onion in butter. Mix all ingredients together and place in casserole. Stir parmesan cheese into casserole and also sprinkle some on top. Bake at 350 degrees for 20-30 minutes.