Drain and wash canned chicken.
Place in the bottom of a mixing bowl.
Drain pineapple and add to bowl with chicken.
Slice grapes in half, add to bowl.
Cut celery into small slices, add to bowl.
Dice onion, if using, and add to bowl.
If water or juice has gathered in bottom of the bowl, pour or drain before adding other ingredients.
Add remaining ingredients to the bowl.
Using a spoon, softly turn together until all ingredients are incorporated.
Refrigerate for 4 or more hours before serving. This recipe tastes better after it has had some time to set.
Serve on bread, rice cakes, or with crackers and vegetables.