Like most everyone who takes pleasure in food, I have a short list of dishes that stand out from the rest—experiences wrapped up in time and place that remain in my mind long after other meals have been forgotten. The peaches that grew on the tree in my yard when I was a kid; poached eggs on creamed spinach from a kosher dairy restaurant in my old neighborhood in Manhattan; the curried chicken dish I still crave from a much missed Cuban Chinese diner where I ate at least once a week for more than a decade. Add to that a squash-blossom quesadilla cooked over an open flame in a Oaxacan marketplace, and truite au bleu at a restaurant in Alsace whose name I can no longer remember.

My list grew a little longer last week after dinner at Sebo, the Hayes Valley sushi bar run by Michael Black and Danny Dunham. This time, the dish that stuck with me was a simple square of tuna, unseasoned and unadorned, that I ate in a single bite. The occasion was a 12-course tuna dinner prepared by Black and Dunham and their friend Chris Cosentino, executive chef at Incanto. The fish that evening was extraordinary for several reasons: First, it was cultivated from an embryo in a lab at the Japanese Kinki University and raised in a low population-density farm without drugs or hormones. Marketed under the name Kindai Honmaguro, these bluefin are considered the ultimate in sustainability and have few of the contaminates—most dangerously mercury—that have put tuna in the headlines. They're also quite difficult to come by. Very little of this tuna makes its way to the U.S., and Sebo is just one of five restaurants in the country to secure a share of this meager supply.


Cosentino and Dunham get meticulous.

But that slice of Kindai is also noteworthy for another reason: It had been sitting in the restaurant's refrigerator for 12 days. It's not that the chefs forgot the fish was there (which happens all the time at my house); instead, they deliberately held onto it, as a butcher does with a fine porterhouse, by way of improving its taste.

The idea of aging goes against everything most of us think we know about fish—mainly that freshness is paramount, and old fish is good for nothing but cat food. But Black gave a very wise, articulate explanation of why that isn't true, how fish benefits from a resting period to achieve its full flavor and texture. The details of what he said

are lost to me now (I blame the 12 glasses of sake—one for each course), but all I need to know about aged tuna became clear with that single bite. As with a great wine, its flavor bloomed while I ate, lingering and changing even after the fish was gone.

There was plenty of culinary shock and awe on the menu that night. Many of the dishes—such as champagne-marinated steak topped with spinal-jelly foam, a cut of the fish's bloodline, spines roasted with orange zest, garlic, and mint, and another dish featuring tuna sperm (thanks, Chris)—were obviously intended to push us diners out of our comfort zone. But the lone slice of tuna that required nothing more from the chefs than the intelligence to leave it alone is what I'll remember long after the tuna sperm has been forgotten.


The "man, woman, child" is prepared with latuma (tuna sperm), egg, bluefin toro, Meyer lemon juice, olive oil, and chives.


Main photo: The head of a bluefin tuna waits patiently on ice.