Wash the potatoes and cut them into bite-sized pieces (about 1-inch cubes) for even cooking. While you're prepping, bring a large pot of salted water to a boil. I like to use Yukon Gold potatoes because they hold their shape better and create a creamier texture in the finished salad. Once the water is boiling, add the potato pieces and cook for 10-14 minutes until they're just tender but still hold their shape—you want them fork-tender but not falling apart.

While the potatoes cook, prepare the flavorful dressing base. In a medium bowl, whisk together the olive oil, Dijon mustard, lemon juice, and lemon zest until well combined. Add the minced garlic, dried dill, dried basil, remaining salt, cracked black pepper, and red chili flakes. Whisk everything together until the dressing is fully emulsified and the spices are evenly distributed. I find that letting the garlic sit in the acid from the lemon juice for a few minutes mellows its raw bite while keeping it vibrant.

When the potatoes are tender, drain them in a colander and rinse with cold water to stop the cooking process immediately. Set aside to cool to room temperature. While the potatoes cool, drain and rinse the tuna under cold water to remove excess liquid, then gently flake it into a small bowl. Finely dice the red onion, chop the cilantro, and finely chop the celery, keeping each ingredient separate for now.

Once the potatoes have cooled to room temperature, transfer them to a large mixing bowl. Add the drained tuna, diced red onion, capers, cilantro, and chopped celery. Pour the lemon dressing from Step 2 over the mixture and fold everything together gently with a rubber spatula, being careful not to break apart the potatoes or tuna too much. The salad is best served at room temperature, where all the flavors shine through together—I find serving it cold dulls the brightness of the lemon and herbs.