Drain Tuna, flake. Mix with sour cream, cucumber, celery seed and celery salt. Toast bread. Spred 1 slice whole wheat toast with tuna salad. Top with 1 slice of white toast. Arrange tomato slices and lettuce. Spread with more tuna salad. Top with second slice whole wheat toast. Cut into forths or triangles and secure with picks or toothpicks to hold in place.
In place of sour cream you can mix 1/2 cup of mayonnaise with a couple of tbsp. of chili sauce or 1 cup of mayonnaise with 1/4 cup of chili sauce to tuna mixture according to your preference.
In place of celery seed and celery salt you can also use 1/4 cup of diced celery.