Drain the cans of tuna into a fine sieve with a bowl underneath, gently flake the tuna to remove any of the excess oil, then transfer the tuna into a large bowl, along with the Greek yogurt, dijon mustard, chopped onion, chopped celery, grated garlic, chopped dill pickels, lemon juice, and season with sea salt & black pepper, mix together until well mixed, add in more yogurt if the mixture is too dry

Lightly toast the slices of whole wheat sandwich bread

Add the tuna salad over the slices of whole wheat toast, top off with slices of tomato, chopped romaine lettuce, and another slice of whole wheat toast, enjoy!