In a small bowl, whisk together the mayonnaise or Greek yogurt, olive oil, lemon juice, and Dijon mustard. Season with salt and pepper to taste and mix until smooth.

Open the can of chickpeas and thoroughly drain and rinse them under cold water. Pat dry with a kitchen towel and peel off any loose skins for a creamier texture.

In a mixing bowl, combine the chickpeas, drained tuna, chopped celery, diced onion, and capers. Toss in dill or your choice of herb, then mix gently.

Drizzle the prepared dressing over the salad and gently stir until everything is well coated and flavors meld together. Serve chilled as desired.