Heat 12-inch nonstick skillet over medium heat. To prepare each quesadilla, brush one side of tortilla with some of the oil. Place tortilla, oiled side down, in skillet. Brush 1 tablespoon enchilada sauce over entire tortilla. Top half of tortilla with 2 tablespoons cheese, 1/4 cup chicken mixture and 2 tablespoons more cheese. Fold other half of tortilla over filling, pressing down slightly.