Open the canned tuna, drain well in a fine mesh strainer, then transfer to a medium mixing bowl. Use a fork to flake the tuna into bite-sized pieces, leaving some chunkiness for texture.

Dice vegetables and eggs

Finely dice the celery, red onion, and dill pickle. Chop the hard-boiled eggs into small pieces. Add the celery, red onion, pickle, chopped eggs, chopped parsley, and capers (if using) to the bowl with the tuna and gently fold to combine.

Dressing

In a separate small bowl, whisk together the mayonnaise, Greek yogurt, Dijon mustard, lemon juice, olive oil, salt, black pepper, and smoked paprika until smooth and homogenous. Taste and adjust seasoning: add more lemon for brightness, more mustard for tang, or more salt/pepper as needed.

Pour the dressing over the tuna-vegetable mixture. Using a spatula or fork, gently fold the dressing into the tuna until everything is evenly coated. Be careful not to over-mash the tuna; aim to keep some chunks for texture.

Cover the bowl and chill in the refrigerator for at least 20 minutes to let flavors meld (optional but recommended). If serving immediately, let sit 5–10 minutes at room temperature for the flavors to marry.

Before serving, taste and adjust final seasoning (salt, pepper, lemon). Serve the tuna salad on mixed greens, in a sandwich, stuffed into tomatoes or avocado halves, or with crackers.