Of all the poke variations I've been sharing this week, this has to be my favorite. For one thing, hamachi is my favorite fish to eat raw. With its rich, buttery flavor and melt-in-your-mouth texture, it's got all of the pleasure of toro with fewer ethical conundrums. It's also the least traditional in flavor, straying pretty far from the standard sesame oil base.
Hamachi is a rich fish that's great eaten in small, nigiri- or sashimi-size bites on its own. In a slightly larger-format dish, like poke, it needs some bright, crunchy counterparts to balance out its richness and prevent palate fatigue. Diced cucumbers are a good start, as is a little heat from a single Thai bird chile. But the real key here is thin strips of lemon zest that I make by peeling a lemon with a Y-peeler, then cutting the zest as thinly as I can with a sharp knife. The secret is to make the initial peel as shallow as you can—the goal is to take the oil-rich, bright yellow zest without getting any of the bitter, pale white pith underneath.
What's amazing is that, while lemon zest itself is not particularly acidic compared to, say, a shot of lemon juice, we have such a strong mental association between the aroma of lemon and acidity that even without actual juice, the zest makes the whole salad taste brighter. This is a useful trick for dishes like this, in which lemon juice would end up adversely affecting the texture of the fish. (Unlike ceviche or tiradito, which acquire a semi-cooked texture through the use of acid, poke should still have the raw tenderness of sashimi.)
Adding just cucumber and lemon zest, plus the classic poke seasoning of soy sauce, sweet onions, scallions, sesame seeds, and sesame oil, would make a fine dish, but as a recipe developer in California, I'm legally obligated to include avocados in a certain number of my recipes to hit quota. This one is a nice home for avocado, whose rich, creamy flesh echoes that of hamachi. I would even suggest that straight-up avocado and cucumber could be used to make a fully vegetarian/vegan poke that would make a great meal on top of some steamed rice.
On a whim, I also decided to try a version substituting some grassy extra-virgin olive oil for the sesame oil.* I liked it even better that way.
*Okay, that "whim" is the fact that my wife, Adri, does not like sesame oil and wanted to participate in the poke party.
Does it lose some of its essential poke-ness without sesame oil? I don't think so. Poke predates the introduction of sesame oil to the Hawaiian Islands, and it has never been a dish that was scared of innovation or customization. In any case, what really matters is that it's delicious, and in my mind, that's all it really needs.