1. Cut cabbage into 1-inch pieces. Cut woody stems from bok choy leaves; slice stems into 1/2-inch pieces. Cut tops of leaves into 1/2-inch slices; set aside.
2. Combine cabbage and bok choy stems in large nonstick skillet.
3. Bring to a boil over high heat. Reduce heat to medium. Cover and simmer 5 minutes or until vegetables are crisp-tender.
4. Blend water into cornstarch in small bowl until smooth. Stir into skillet. Cook and stir 1 minute or until sauce boils and thickens.
5. Stir in reserved bok choy leaves; cook 1 minute. serve as desired.