1Mix broth, soy sauce and cornstarch; set aside. Separate bok choy leaves from stems. Cut leaves and stems into 1-inch pieces.
2Heat oil in 12-inch nonstick skillet or wok over medium-high heat. Add bok choy stems, onion, garlic and gingerroot; stirring constantly cook 2 minutes. Stir in bok choy leaves and mushrooms. Cook 1 minute, stirring constantly.
3Stir in broth mixture. Cook, stirring constantly, about 4 minutes or until thickened. Stir in cashews.