Deviled eggs

6 hard cooked eggs, cut in half
1/4 cup mayonnaise
1/4 teaspoon salt
1/4 teaspoon pepper
2 teaspoons prepared mustard
1 tablespoon finely chopped celery
1 tablespoon finely chopped stuffed olives
1 tablespoon finely chopped onion

Remove egg yolks. Mash and combine with remaining ingredients. Refill egg whites. Chill. Trim with slice of stuffed olive in each egg.