For meal prep, store the tuna salad in an airtight container in the refrigerator for up to 3 days and keep the washed, dried lettuce leaves wrapped in paper towels in a separate container so they stay crisp. If your avocado is very ripe and soft, the tuna salad will be creamier, so you may wish to reduce the mayonnaise slightly or add a little more tuna to balance the texture. To keep net carbs low, choose sugar-free mayonnaise, Dijon mustard, and pickles, and avoid sweet relishes or condiments with added sugar. If serving as an appetizer or snack, use smaller lettuce leaves to create bite-size cups and secure them with toothpicks if needed for easy handling. This recipe is naturally gluten free and works well alongside sliced cucumbers, olives, or a simple green salad for a complete keto meal.