4 cans white flaked tuna
1 cup mayonnaise
2 Tablespoons pickle relish
1 stalk celery
2 Tablespoons red onion
1 teaspoon Dijon mustard
2 teaspoon lemon juice
¼ teaspoon salt
¼ teaspoon pepper
1 teaspoon garlic powder
Bread, lettuces, avocados etc. for serving