While fettuccine is cooking, heat oil in 12" skillet over medium-high heat. Cook broccoli, cauliflowerets, carrots, peas and onion in oil 6 to 8 minutes, stirring frequently, until vegetables are crisp-tender.
Stir in Alfredo sauce; heat through. Drain fettuccine. Stir fettuccine into sauce mixture; heat through. Sprinkle with cheese.