COOK pasta as directed on package.
MEANWHILE, spray large nonstick skillet with cooking spray. Heat on medium heat. Add mushrooms; cook 3 to 5 min. or until tender, stirring frequently. Drain mushrooms; discard liquid. Return mushrooms to skillet. Add sausage and onions; cook 6 to 8 min. or until sausage is no longer pink, stirring occasionally. Stir in sauce; cook 5 min. or until heated through, stirring occasionally.
DRAIN pasta; place on serving platter. Top with the sauce; sprinkle with cheese.