Drain the canned tuna and transfer it to your mixing bowl. Use a fork to flake and break apart the chunks of tuna, ensuring even distribution. This step is essential to make the tuna more tender in every bite and to make the tuna salad taste cohesive.

In a separate bowl, scoop out the avocado flesh and mash with a fork. Aim for a mostly smooth paste but leave some chunks of avocado for texture. This mash will serve as the creamy base, replacing traditional mayonnaise or mayo.

Add the mashed avocado to the tuna, then toss to combine. Next, add the diced celery, sliced red onion, and cilantro. Stir gently so as not to break down the tuna flakes too much—this creates a pleasing chunky texture.

In a small bowl, whisk together lemon juice, mayonnaise (if using), and a drizzle of olive oil. Pour over the tuna mixture and toss to combine, ensuring every bit is coated in the tangy dressing.

Finally, taste and season with salt and pepper as needed. Adjust acidity with more lemon juice if desired. Your salad is now ready to serve or store for later.