The walnut is the one ingredient on our menu whose homeland is this very soil. The tree botanists call Juglans regia, the royal walnut, grew around Anatolia and the Caspian thousands of years ago, and traveled east and west in the saddlebags of Silk Road caravans. There was a handful of walnuts on the road to Rome, and another on the road to China. The Chinese named it hu tao 核桃; by the time it reached Japan it had become kurumi 胡桃, folded into mochi, sweet sauces, celebration dishes.

So the walnut’s story runs opposite to our kitchen’s: sushi came from east to west; the walnut went from here to the east. The two roads cross on this plate.

To caramelize is to seal the walnut’s earthy depth inside the glassy shine of sugar. The craft speaks in seconds: a pot pulled early stays sticky, a pot pulled late turns bitter. Poured at the right instant, the walnuts set a thin shell of glass as they cool.

Among sushi it may look like an unexpected guest. The first crunch clears the matter up; not a guest at all, but the host.