Corri's Chicken Salad

2 cups chicken, baked and finely diced
½ cup celery, finely diced
½ medium onion, finely diced and simmered lightly in butter until tender
2 cups apple, finely diced
1 cup grapes, halved
1 20 oz. can pineapple tidbits, well drained
1 cup mayonnaise
¼ tsp salt
Pinch black pepper

Combine the mayonnaise, onion, salt and pepper; chill several hours or overnight. Combine chicken, fruits, and vegetables; stir in the mayonnaise mixture. Serve right away or cover and chill until serving. Serve with croissants.