HEAT oven to 450ºF.
HEAT 3 Tbsp. dressing in medium skillet on medium heat. Add peppers and garlic; cover. Cook on low heat 10 min. or until peppers are tender, stirring occasionally. Spread onto pizza crust; top with chicken, onions, tomatoes and mozzarella.
BAKE 12 min. or until mozzarella is melted.
TOSS salad greens with remaining dressing; spoon over pizza. Serve immediately.