Bring chicken broth to a boil in 5-quart saucepan. Add wild rice. Cover; reduce heat to medium-low; simmer 40 minutes. Add white rice; cover and cook 20 minutes or until wild rice grains have popped and are tender. Let stand, covered, 5 minutes.
Heat 2 tablespoons butter in large skillet over medium heat. Add onion and green beans; cook, stirring, 5 minutes. Add mushrooms; cook 5 minutes, until mushrooms release their liquid. Season with salt and pepper. Add sherry; cook 4 minutes. Stir in rice, or combine mushroom mixture with rice in large bowl. Stir in remaining 1 tablespoon butter. Makes 6 servings.
