Mix salt, sugar, lemon zest, allspice, and Lapsang Souchong tea.
Moisten the salt and sugar mix with bourbon and cover the tuna steak with it.
Put the fish in a non-reactive container, seal, and marinate for 24 hours, flipping it once after the first 12 hours.
Remove cured tuna from the marinade, clean, and pat dry. It will keep for up to two weeks refrigerated.
Slice cured tuna for serving.
You can make variations replacing lemon zest with lime or orange. Instead of smokey flavors, try adding small amounts of herbs like tarragon. The recipe at luxirare uses gin with lime zest and an assortment of peppercorns. If you like fruity flavors of high quality bourbon, you might also like to experiment with your favorite cognacs or grappas. You won’t feel the alcohol in final product at all, only its characteristic flavors.