Open the canned tuna and drain thoroughly. Transfer tuna to a medium mixing bowl and use a fork to flake it into small pieces, breaking up large chunks but leaving some texture.

Prepare vegetables and eggs

Finely dice the celery, onion, and pickles. If using hard-cooked eggs, peel and chop them into small pieces. Chop the fresh parsley. Add all of these to the bowl with the flaked tuna.

Season

Add the measured salt and black pepper to the tuna-vegetable mixture and gently toss to distribute before adding the dressing. This helps layer the seasoning evenly.

Dressing

In a separate small bowl, whisk together the mayonnaise, Greek yogurt (or sour cream), Dijon mustard, lemon juice, olive oil, and optional sugar or honey until smooth and homogenous. Taste and adjust seasoning — add a little more lemon for brightness or a pinch more salt if needed.

Pour the dressing over the tuna mixture. Gently fold the dressing into the tuna and vegetables using a spatula or large spoon until everything is evenly coated. Be careful not to overwork; the salad should be cohesive but not mushy.

Cover the bowl and refrigerate for at least 30 minutes to let flavors meld. Taste again before serving and adjust salt, pepper, or lemon juice if necessary.

Serve chilled or at cool room temperature. Suggestions: serve on mixed greens, in sandwich bread, on croissants, or scooped into avocado halves. Keeps well refrigerated in an airtight container for up to 3 days.