I order the tuna tartare appetizer probably every time I go out to a nice (meat) restaurant. I don’t make it for myself at home because there’s no one else in my house that will eat fish this raw (though I do have some customers for seared tuna steak, which some members have finally realized is amazing). Come Yom Tov time, or any time that there will be more diverse eaters available, though, serve it as little appetizer bites on refreshing cucumber and your tiny bit of tuna will stretch a really long way. This version is a little different because it has more ingredients in there and a little crunch from the panko and sesame. If you want to prep this earlier in the day, keep the tuna, mango, and avocado each separate. Keep the liquid ingredients separate. Panko and sesame can be stored together. Then toss together when ready to serve. Lime cooks the tuna so if you leave this for long it will turn into ceviche.