In a large skillet or wok, cook beef over medium heat until no longer pink; drain and set aside. In the same pan, stir-fry the asparagus, water chestnuts, mushrooms and garlic in oil for 5 minutes or until crisp-tender.
In a small bowl, combine cornstarch and broth until smooth. Stir in the hoisin sauce, soy sauce and ginger. Pour over vegetables. Return beef to the pan. Bring to a boil; cook and stir for 2 minutes or until thickened. Remove from the heat; stir in tomato. Serve with rice if desired.