Creating Avocado Tuna Salad Lettuce Wraps is straightforward. Just follow these simple steps:

1. Drain Tuna: Open the can of tuna and drain any excess liquid.
2. Mash Avocado: In a bowl, mash the ripe avocado with a fork until smooth or slightly chunky, based on your preference.
3. Combine Ingredients: Add the drained tuna, mayonnaise (if using), Dijon mustard, lemon juice, chopped celery, and diced red onion to the mashed avocado.
4. Mix Well: Stir the mixture until all ingredients are well combined. Season with salt and pepper to taste.
5. Prepare Lettuce Leaves: Carefully separate the leaves of the Romaine or Butter lettuce, rinsing them gently to remove any dirt.
6. Assemble Wraps: Spoon a generous amount of the tuna salad mixture onto the center of each lettuce leaf.
7. Add Optional Toppings: If desired, add cherry tomatoes, cucumber slices, or sprouts for extra crunch and flavor.

And just like that, your Avocado Tuna Salad Lettuce Wraps are ready to be enjoyed!