Cut each chicken breast half into four lengthwise strips. On each of eight 6-inch skewers, thread 2 each of the chicken strips, pineapple, and sweet pepper.
For dressing, in a screw-top jar combine vinegar, water, salad oil, soy sauce, sesame oil, and dry mustard. Cover and shake well. Reserve 2 tablespoons of the dressing. Cover remaining dressing; chill until needed.
Stir together the 2 tablespoons reserved dressing and plum sauce or chili sauce. Brush over kabobs.
Grill kabobs on the rack of an uncovered grill directly over medium coals for 10 to 12 minutes or until chicken is tender and no longer pink, turning once halfway through grilling.
Combine the red cabbage and bok choy or lettuce; divide greens mixture among 4 dinner plates. Top with kabobs, pea pods, and mushrooms. Shake chilled dressing; drizzle over salad.