1. Cook pasta in large saucepan as directed on package, omitting salt.
2. Meanwhile, sprinkle chicken with pepper. Heat 1 tbsp oil in large nonstick skillet on medium heat. Add chicken; cook 5-7 minutes on each side or until done. Remove to plate; cover to keep warm. Add remaining oil to same skillet. Add squash; stir-fry 3 minutes. Add garlic; stir-fry 3 mins. Or until squash is crisp-tender.
3. Drain pasta, reserving 1/4 cup cooking water. Toss pasta with reserved water in same pan; place in large serving platter. Top with chicken, squash and remaining ingredients.