1Heat oven to 400°F. Spray 11x7-inch (2-quart) glass baking dish with cooking spray. Cook green beans as directed on bag; set aside.
2Meanwhile, in 3-quart saucepan, melt 1/4 cup of the butter over medium-high heat. Cook onion in butter 4 minutes, stirring occasionally, until tender. Reduce heat to medium. Sprinkle onion with flour; cook 3 minutes longer, stirring constantly. Stir in broth. Heat to boiling. Remove from heat. Stir in black pepper, salt, red pepper and sour cream with wire whisk until blended. Stir in green beans. Spoon mixture into baking dish.
3In medium microwavable bowl, microwave remaining 1/4 cup butter uncovered on High until melted. Add bread crumbs and cheese; mix until blended. Sprinkle evenly over green bean mixture.
4Bake uncovered 20 to 23 minutes or until bubbly and topping is golden brown.