MIX first 5 ingredients until blended. Reserve 1/3 cup mustard mixture; refrigerate for later use. Pour remaining mustard mixture over combined shrimp, chicken and vegetables in shallow dish; stir to evenly coat ingredients with mustard mixture. Refrigerate 2 hours to marinate.
HEAT gill to medium heat. Drain marinated ingredients; discard marinade. Thread chicken, shrimp and vegetables alternately onto skewers.
GRILL 8 to 10 min. or until shrimp and chicken are done, turning occasionally. Meanwhile, cook reserved mustard mixture until heated through. Place skewers on platter; drizzle with mustard mixture.