COOK pasta as directed on package.
MEANWHILE, cook sausage in large nonstick skillet on medium heat until evenly browned, stirring occasionally. Drain; return to skillet. Stir in onions and tomato paste; cover. Cook 15 min. or until onions are tender and sausage is done, stirring occasionally. Stir in dressing.
DRAIN pasta; place in large bowl. Add sausage mixture; mix lightly. Top with parsley and cheese.