tuna fish was a hard sell in my house. my husband hates mayonnaise more than any other food product out there. i mean he hates it so much, i don't even keep it in my house, hates it. so, in order to get any "mayo" effect, i turn to greek yogurt (fage, because that is the only brand i have tried and have been completely satisfied with) or plain fat free yogurt. i personally think it tastes better than mayo. for this sandwich i used about 1/4 cup of fat free plain yogurt, a heaping spoonful of dijon mustard (please don't use that yellow stuff you put on hot dogs at a fair, go buy dijon.), a splash of worchestershire, garlic powder, onion powder, celery seed, curry powder, a splash of white wine vinegar and one can of albacore tuna, drained. as you can see i also added bacon. easy now, it was only one slice! add whatever you like, shredded lettuce, thinly sliced onion, tomato, shredded carrot even? by the way, i generally never have bacon around. so, when i have any left over from the package, which i always do, i freeze the remainder. i take two slices of bacon, wrap it in plastic wrap, and store in my freezer. when i want to have a slice of bacon for a "special" egg white sandwich for breakfast on the weekends, i simply pull it out of the freezer. it only takes about 15 minutes to defrost. it's a nice weekend splurge. this big tuna is light and goes perfectly with a homemade bowl of soup or salad. you will be left satisfied and full!