1. Cook pasta as directed on package, omitting salt; keep warm.
2. Heat oil and red pepper flakes in medium non-stick skillet on medium-high heat. Add onions; cook 3-4 min. or until softened, stirring frequently. Add peppers and zucchini; cook 3 min. or until vegetables are crisp-tender.
3. Warm sauce in same pot on medium heat. Stir in greens and cook just until wilted. Stir in cooked pasta. Divide mixture among 6 serving bowls.
4. Top evenly with vegetable mixture and remaining ingredients.