Combine tuna, mayonnaise, relish and celery in a medium bowl.
Salt and pepper to taste.
Divide the tuna salad.
Place inside cabbage leaf. You can leave it open for a bowl, or roll it like a burrito and place a toothpick in it to hold it.
Even though I gave you exact measurements this is a recipe that is per your taste. Meaning that you can add your ingredients per your liking. There’s no right or wrong way to make this tuna salad bowl/wrap.