Cut each chicken breast half lengthwise into 4 strips. Thread 2 of the chicken strips on each of eight 6-inch wooden skewers. Place in a 2-quart rectangular microwave-safe baking dish; set aside.
For sesame dressing, in a screw-top jar combine salad oil, rice or white wine vinegar, toasted sesame oil, soy sauce, dry mustard, and crushed red pepper. Cover and shake well.
Stir together 2 tablespoons of the sesame dressing and plum sauce; brush over kabobs. Cover dish with waxed paper and microwave on high 2 minutes. Turn kabobs over, rearrange in dish, and brush again with the dressing mixture. Microwave for 2 to 4 minutes more or until chicken is no longer pink.
Meanwhile, combine cabbage and bok choy; divide among 4 plates. Top with kabobs, pineapple, sugar snap peas, mushrooms, and radishes. Drizzle sesame dressing over salads. If desired, sprinkle with sesame seed. Makes 4 servings.