I have made these several times now, but I substitute chicken for tuna. They are always a hit and disappear quickly. I use the Tyson cooked chicken in pouches that are right next to the tuna or the canned chicken and it is delicious! The pink lady apples are a perfect addition. I often do not add celery or onion, again that is our taste - but just the combo of chicken/tuna salad, apples, and havarti cheese in the tartlets is perfect.