I replaced the tuna with salmon in this fresh spring salad.
Yuzu is a small irregular fruit, which in taste resembles a lemon, but also has the flavor of other citrus fruits. The taste of yuzu is less hard and sharp than that of a European lemon. I compare it a bit with a sour mandarin. It is a reasonably expensive product, I sometimes replace it by making a mix of lime juice and lemon juice and mandarin juice.