Mahi Mahi is semi-mild and sweet tasting. It's similar to halibut in terms of flakiness, but also similar to swordfish in its denseness. If you can't find mahi mahi, you can substitute either halibut or swordfish for it.
sour cream
minced fresh ginger root
lime juice
cumin
cayenne pepper
salt
pepper
mahi mahi fillets (or halibut or swordfish)