Preheat oven to 350°.
Heat oil in a nonstick skillet over medium- high heat. Add onion and celery; sauté 4 minutes or until onion is golden.
Increase heat to high; add water. Bring to a boil, and cook 4 minutes or until celery is tender. Stir in spread until melted. Add soup, stuffing, and pepper. Remove from heat, and stir in chicken.
Place stuffing mixture in a 2-quart baking dish coated with cooking spray. Bake at 350° for 45 minutes or until top is golden.