In a large saucepan, SAUTE onion in butter; BLEND in flour, salt and pepper.
ADD sour cream, STIRRING constantly; COOK until smooth and bubbly.
STIR in beans; POUR mixture into a shallow baking dish; SPRINKLE cheese on top.
BAKE at 350° for 12 - 20 minutes.
Use either packaged "French style" green beans or fresh green beans, cooked.
Per Serving (excluding unknown items): 189 Calories; 16g Fat (74.3% calories from fat); 6g Protein; 6g Carbohydrate; 1g Dietary Fiber; 35mg Cholesterol; 401mg Sodium. Exchanges: 0 Grain(Starch); 1/2 Lean Meat; 1/2 Vegetable; 0 Non-Fat Milk; 3 Fat.