Peru and Japan each have one representative in the main kitchen, where two chefs, Mina Newman and Taku Nagai, share power. Ms. Newman is a New Yorker who spent summers as a child in Chiclayo, the city in northwestern Peru where her mother was born. Mr. Nagai, an Osaka native, is a veteran of Japanese restaurants in New York and Asia. The two generally keep up with the number of seats and the size of the menu, although waits between courses sometimes drag.
The dining room staff doesn’t seem as well organized. My servers were cheerful and communicated well with customers, but not necessarily with each other. Three people in a row would stop by to ask the same question, and just clearing the table seemed to take a cast of hundreds.
A third chef, named Sang Hyun Lee, presides over the free-standing sushi bar. His work ranges from simple, classic nigiri and sashimi to psychedelic, 10-ingredient inside-out rolls that might make Jiro Ono cross-eyed.
Sen Sakana’s best sushi is somewhere in between: what Mr. Lee calls Nikkei sashimi and nigiri. Augmented with Peruvian or Japanese flavors, these pieces are only slightly out of bounds, and can be delicious. There’s pleasurable tension in topping raw scallop with a tiny fleck of yuzu-ponzu jelly and commas of shaved lemon peel, or brushing sea bream with a tart, spicy sauce of yuzu and aji amarillo, then dotting it with a tiny bit of salted plum paste. Add six more things and they would all start to collide somewhere over the Pacific.
One dessert is a small waffle made from batter that contains squash and sweet potato, a homage to Peruvian picarones, with a dark molasses syrup. Another is a shallow-pan chocolate tres leches cake, which tasted something like a dense brownie over which somebody poured a glass of cocktail de algarrobina, Peru’s answer to eggnog. It had never occurred to me to soak a brownie in eggnog. “Does this make sense?” I asked, between bites, until it was gone.