Ahi Tuna Burger

Order an ahi tuna burger and the server asks how you want it, which is a question a beef burger rarely draws and one the kitchen answers with "rare" more often than not. The fish is yellowfin or bigeye, the two tunas Hawaii calls ahi, and it reaches the bun in one of two shapes. A steak is trimmed to the width of the bun and about an inch thick. A chopped patty is hand-minced tuna folded with a little egg white or panko, ginger, and scallion so the pieces cling to each other. Either way a bun encloses seared tuna with a pink or ruby center, and the whole build is arranged around keeping that center cool.

The sear takes a minute or two a side over high heat, against the five or six minutes a beef patty takes. Oil hisses the moment the fish lands, and if sesame seeds were pressed into the crust the kitchen fills with a nutty, toasting smell within seconds. A steak cut thick browns a quarter-inch band and keeps a cold, glossy middle. Left on past that, lean tuna turns dry and crumbly and tastes like the canned fish it is often compared to. A chopped patty has more surface to brown and less margin: minced tuna worked too hard turns tacky and sticks to the steel, so cooks shape it gently with wet hands and flip it once.

Tuna carries almost no fat, so the dressing supplies the richness the fish lacks. Wasabi mayonnaise is the usual choice, smeared on the toasted bun where it softens against the heat, with pickled ginger or a shredded cabbage slaw for crunch and a slice of avocado on builds that want more cream. Brioche and potato buns are the common vessels because they compress around a soft, rare center instead of fighting it. The first bite is warm bread, then a cool, almost silky interior that parts like sashimi under the teeth, then a sinus-clearing hit of wasabi that fades before the soy glaze or the sweetness of the bun settles back in.

Menus in Hawaii and on the California coast tend to list it as the lighter alternative to the beef burger, often at market price and often at a beach or harbor café where the fish came off a boat that week. The variations stay close to the griddle. Sesame-crusted versions press black and white seeds into the sear, blackened ones use a Cajun-style rub, teriyaki-glazed ones lacquer the surface in the last thirty seconds, and a tataki build slices the seared steak thin before it goes on the bun. The ahi poke sandwich takes the same fish in raw cubes tossed in shoyu, and this one browns it whole.

Cooks who grind tuna for the patty usually start from trim, the ragged pieces left when a loin is squared off for sashimi, which makes the chopped burger one of the cheaper ways to put good fish on a lunch menu. Chopped by knife into pieces about the size of a pea, the fish keeps a coarse, meaty bite. Run through a grinder, it becomes a smooth paste that cooks to a firmer, springier patty. The two textures draw different loyalties, and menus rarely say which one is coming until the plate lands.

Fish on a bun, before the fresh ahi

Fish on a bun was already an American lunch long before fresh ahi reached it. Midcentury Friday menus carried tuna patties made from canned fish for Catholic customers who skipped meat, and in 1962 a McDonald's franchisee named Lou Groen put a fried fish sandwich on the menu at his Monfort Heights restaurant outside Cincinnati; accounts of his Good Friday sales that year vary, though he reportedly sold several hundred. Those sandwiches used cod or canned tuna, cooked all the way through, and carried no suggestion of a rare center.

The fresh fish came from the Pacific. The Honolulu Fish Auction, run by the United Fishing Agency, opened on August 5, 1952, founded by Matsujiro Otani, and sells ahi one fish at a time to restaurants and markets. In August 1991 twelve chefs, among them Sam Choy and Roy Yamaguchi, met at the Maui Prince Hotel and launched Hawaii Regional Cuisine, which put local fish at the front of restaurant menus. No record names the cook who first seared an ahi steak onto a bun, or the year.

The rare center rests on a rule about parasites. The FDA Food Code requires most fish served raw or undercooked to be frozen first, and a kitchen holding a fresh ahi loin can sear it and serve it pink without that step, with a consumer advisory on the menu. The exemption is written into the Food Code's 2013 edition, which lists yellowfin, bigeye, and both bluefin species among the tunas that need no parasite freezing.