Slice beef across the grain into thin strips. In medium bowl, combine steak, 1 tablespoon cornstarch, soy sauce and sherry.
Dissolve remaining cornstarch in beef broth and reserve.
Heat 1 tablespoon oil in large skillet. Add beef and garlic. Cook over high heat, stirring constantly, until browned, about 3 minutes.
Add remaining oil. Add snow peas and bean sprouts. Stir-fry 1 minute. Add beef broth mixture; cook and stir until thickened, about 2 minutes. Garnish with walnuts. Makes 4 to 6 servings.