2 (10 oz.) pkgs. frozen spinach, chopped
1/2 c. onion, finely chopped
1/2 stick butter
1 can water chestnuts, sliced
1 c. plain yogurt
1 tbsp. flour
1/4 tsp. garlic powder
1/2 c. parmesan cheese, grated
Salt and pepper, to taste

Cook spinach as directed on box. Saute onion and butter. Mix all ingredients and place in casserole. Sprinkle additional parmesan cheese on top. Bake at 350 degrees for 45 minutes.