COOK pasta as directed on package, omitting salt.
MEANWHILE, cook bacon in large skillet until crisp. Remove bacon from skillet with slotted spoon; drain on paper towels. Discard all but 1 Tbsp. drippings from skillet. Add dressing, peas and onions; cook and stir 3 to 4 min. on medium heat or until peas are heated through.
DRAIN pasta, reserving 1/4 cup of the cooking water. Place pasta in large bowl. Add vegetable mixture and bacon; mix lightly. Gradually stir in reserved pasta water, if needed, until pasta mixture is of desired consistency. Top with cheese.