Begin by opening two cans of solid white albacore tuna. Drain the excess liquid thoroughly to avoid a watery salad, then flake the tuna into a large mixing bowl using a fork.

In a separate bowl, combine ¼ cup of mayonnaise with ¼ cup of Greek yogurt. Add 1 tablespoon of Dijon mustard, the juice of half a lemon, and 2 tablespoons of sweet pickle relish. Season with salt and pepper to taste. Whisk until smooth.

Gently fold in ½ cup of diced celery, ¼ cup of finely chopped red onion, and 2 tablespoons of fresh dill into the flaked tuna.

Carefully toss the prepared dressing into the tuna mixture and mix gently until everything is just combined.

Cover your bowl with plastic wrap and refrigerate the tuna salad for at least 30 minutes.

When ready to enjoy, assemble your sandwich by laying fresh lettuce on one slice of bread, scoop the chilled tuna salad on top, and add optional tomatoes and onions. Complete with another slice of bread.