Tuna Celery Stalks

1 can low-sodium chunk white tuna,rinsed and drained
1 tablespoon balsamic vinegar
1/4 cup finely chopped onion
1/4 cup finely chopped apple
2 tablespoons fat-free plain yogurt
ground black pepper
12 ribs celery,rinsed and ends trimmed

directions

1. put the tuna in a small bowl and break it apart with a fork. add vinegar and mix.
2. add onion,apple,yogurt,and pepper to taste. mix well
3. spoon tuna salad into gutter of each rib