Saute celery and onion in butter in large skillet until tender.
Mix water, salt and pepper with beaten egg.
Combine celery mixture, egg mixture and bread crumbs.
Toss lightly.
Using a 1/4 cup measure, shape into balls.
Place in paper baking cups set in muffin tins.
Bake for 20 min or until lightly browned at 375 degrees