The rice-making is easy, and far from mysterious. You need good short-grain white rice (you can use brown rice, of course, but it’s not the same thing), rice vinegar, sugar, salt and kelp (or konbu, a kind of seaweed). Some sake is nice, but it is not essential. You blend the vinegar, sugar, salt and kelp, remove the kelp, then let the sweetened vinegar (now called awasezu) sit at room temperature or in the refrigerator for as long as you like. (I haven’t tested to see how long it will last, but several days are certainly fine.)

You cook the rice, adding a little sake to the water if you have it; the proportions are about one-and-a-half parts water to one part rice, though you can get away with less water if you have a rice cooker.

When the rice is done, you let it sit for 15 minutes or so, then you fold in about a half-cup of awasezu for every two cups of cooked rice. You do this gently, so as not to crush the rice, but it’s not as painstaking a process as it’s sometimes made out to be.

If your goal is to become a great sushi chef, you can take this more seriously. But for me, it seemed the rough equivalent of folding egg whites into a batter. The rice will absorb more awasezu than it needs, so you have to keep tasting and stop when you have the right, slightly sweet-and-sour flavor.

Image Among the vegetables on the dish above are eggplant, wasabi mountain yam, Japanese plum and mustard greens. Credit... Rebecca McAlpin for The New York Times

Forming the rice looks easier than it is. The rice is very sticky, so you need to wet your hands between forming each piece. (You’ll note that most sushi chefs do this, too.) Mr. Ueki proceeded to rip off shapes of all kinds: hand-molded nigiri, mat-rolled maki, a kind of “box” sushi called oshigata that is popular in Osaka. (I bought a gadget for making oshigata for $5 online; it works), and a variety of less-formally molded shapes. These, when I got home and began to work myself, turned out to be my favorite. Even a nicely formed nigiri sushi can take some time.

Once I got the hang of it, I was producing hand rolls in a variety of forms without much trouble. Ultimately I found three favorites. First is a quarter sheet of nori, smeared lightly with rice (about a tablespoon, not much more) and topped with a couple of bits of whatever  say umeboshi and tofu  then rolled, cigar- or cone-like. Next is a small rounded pile of rice (again, about a tablespoon) with, say, a pile of chopped seasoned greens on top and a thin band of nori wrapped around its side (like the popular sushi made with uni). Finally, a small pile of rice, crudely shaped but vaguely nigiri-ish, with something on top  prosciutto turned out to be my favorite. (I never said these were vegan.) All of these were crude yet recognizable forms of shapes that Mr. Ueki had demonstrated.