Chef Hackett says to sear the tuna in a light flavorless oil such as grape seed oil, so as not to detract from the flavor of the salt-cure or the tuna itself.
12ounces sushi-grade Hawaiian ahi tuna loin, fabricated into a rectangular bar
1ounce Old Istanbul Blend from Juliet Mae (an exotic blend of Turkish spices and chiles)
1/4ounce coriander seed, toasted and coarsely ground
1/4ounce cumin seed, toasted and coarsely ground
1/2ounce ground Marash chile pepper (a Turkish chile pepper that resembles Aleppo pepper)
1/4ounce black peppercorn, coarsely ground
1/4ounce pink peppercorn, coarsely ground
2ounces sea salt, finely ground
1ounce black sea salt, finely ground
1ounce granulated sugar
Zest of 1 orange and 1 lime
2ounces high-quality sherry wine
Grape seed oil for searing
In a stainless steel nonreactive bowl, mix together all of the dried spice ingredients along with the salt, sugar, and orange and lime zest.
Using a pastry brush coat the ahi tuna bar on all sides with a liberal amount of sherry wine. Then place the sherry-coated tuna bar into the stainless steel bowl with the dried spice mix. Using your hands, gently press generous amounts of the salt-spice cure mix onto each of the 4 sides of the tuna bar.
Place the spice- and salt-covered tuna bar on a roasting rack set over a sheet pan to catch the drippings from the tuna as it cures in the refrigerator. Allow it to cure for at least 24 hours, but no more than 36 hours.
When ready to serve the tuna, remove it from the refrigerator and brush away the dried spice-salt cure from all sides. Heat some grape seed oil in a sauté pan to very hot and quickly sear the ahi on all four sides. Allow it to cool completely and then using an extremely sharp slicer, portion the tuna into equally thin perfect slices. Serve with a salad of lightly pickled cucumbers garnished with cilantro and thin slices of ripe avocado.