Prepare the Dressing: Whisk together mayonnaise or Greek yogurt, extra-virgin olive oil, fresh lemon juice, dijon mustard, kosher salt, black pepper, and hot sauce in a medium bowl until well combined.
Mix the Base Ingredients: In another large bowl, combine the drained chickpeas and tuna. Use a fork to gently break up the tuna into smaller pieces while ensuring the chickpeas remain intact.
Add Fresh Vegetables and Herbs: To the tuna and chickpea mixture, add finely chopped celery, minced red onion, fresh dill, and your choice of capers or olives.
Combine Everything Together: Pour the dressing over the salad mixture and carefully fold everything together until all ingredients are coated evenly with dressing.
Serve Immediately or Chill: Serve this salad immediately over arugula or whole-grain bread, or let it chill in the refrigerator for about 30 minutes.