Tuna salad is typically a blend of two main ingredients: tuna and mayonnaise or mayonnaise-substitute. Chopped hard-boiled egg, celery or relish, and onion are ingredients that are often added. Tuna salad is regularly served on top of lettuce, tomato, avocado, or some combination of these. The tuna used is usually pre-cooked, canned, and packaged in water or oil.
Quick homemade tuna salad is often made by omitting the eggs and adding sweet relish. The reason for the change is that the eggs must be cooked whereas the other ingredients are purchased ready to eat. When the spread is placed on bread, it makes a tuna salad sandwich.
In Belgium, the dish pêches au thon / perziken met tonijn is made from halved canned or fresh peaches stuffed with tuna salad.