COOK onions in large skillet sprayed with cooking spray on medium-high heat 5 min. or until crisp-tender, stirring occasionally.
ADD next 4 ingredientsr; stir. Bring to boil. Stir in turkey; cover. Simmer on medium-low heat 10 min.
TOP with cheese. Remove from heat. Let stand, covered, 3 min. or until cheese is melted. Serve with tortillas.