In a small saucepan, heat oil over medium heat. Add onion and celery; cook until tender. Stir in cranberry sauce, sour cream, and vinegar.
Stirring occasionally, bring to a boil over medium heat and cook 15 minutes or until thickened Remove from heat; set aside. Preheat oven to 375° F. Spray each sheet of phyllo pastry with cooking spray.
Stack pastry sheets on top of each other; cut into eighteen 3-inch squares. Press 1 pastry square into each tin of a greased miniature muffin pan. Place 1 piece cheese in center of each pastry square. Spoon a heaping teaspoonful cranberry mixture over top of each piece of cheese. Bake 12 to 15 minutes or until golden brown.Servings: