COOK noodles in boiling water 5 min. or until tender. Meanwhile, cook and stir chicken and garlic in 2 Tbsp. dressing in wok or large skillet on high heat 5 min. or until chicken is cooked through. Stir in egg; cook 30 sec. or until set.
DRAIN noodles. Mix remaining dressing, water, peanut butter and soy sauce in wok. Add noodles; mix well. Add sprouts and onions; toss lightly. Top with peanuts. Serve immediately.