It makes you feel good and it's addictive. It's also healthy. There aren't too many things you can say that about. Japanese food is as big a trend as Thai was 10 years ago, according to Jennifer Glynn, head chef at Aya at Brown Thomas. Even the Chinese community and - wonder of wonders - young children are into it, she says.
Two weeks ago, Aya opened a new outlet in Donnybrook, Dublin, and they have plans for another deli/sushi outlet in the Financial Services Centre. Aya's sushi robots also supply 10 Tesco stores. Who'd have thought we'd see the day when you could pick up sushi with your sliced pan?
Another Japanese restaurant, Miss Sushi, in the Epicurean Food Hall on Middle Abbey Street in Dublin, has catered for gatherings as varied as Fine Gael constituency meetings, bar mitzvahs, clubs (Viva, Gubu, Wax) and sushi-loving rock stars like Nick Cave. MCD, which manages concerts, tend to ring up Miss Sushi at the spur of the moment to satisfy the backstage cravings of their talent.
Sushi comes in two basic varieties. Maki comes in little circles of rice with fish or vegetables, surrounded by paper-thin black Nori seaweed (cultivated since the 17th century). Nigri consists of raw fish layered on top of a small mound of sushi rice.
Laois-born Margaret Scully, 34-year-old owner of Miss Sushi, became a sushi addict while living in Hong Kong, which is why she decided to open her business in Dublin a year ago. If you've had sushi in Nude or Insomniacs restaurants, it was supplied by Miss Sushi and made by Margaret's ace sushi chef Amos.
The Japanese have the longest life expectancy in the world, living five years longer than the Irish on average. Japanese women have low rates of breast cancer, which rise only when they move to the West and adopt Western diets.
Marilyn Glenville, in Natural Alternatives to HRT (Kyle Cathie), writes that Japanese women don't experience menopausal symptoms. Japanese health - which extends right through the last decades of life - is even more extraordinary considering that Japanese life is high-density, urban, polluted and stressful, Scully comments.
The way real Japanese people eat at home is the healthiest of all: grilled or steamed fish, steamed vegetables and rice is the staple diet. Sushi is a treat bought in restaurants.
In Japanese restaurants in Ireland, like Aya, you'll get a nod to Western cuisine; and many people order tempura, which is deep-fried. Japanese people don't eat tempura at home. But still, even with a Westernised menu, there are no sauces, lots of fresh fish, plenty of vegetables and - in most dishes - very little fat.
"Sushi feels good in your mouth and your body. You feel replenished after eating it, it's filling but light and tasty," Scully says.
She would say that, wouldn't she? Fortunately, the nutritional evidence backs her up. Sushi is a high-protein, vitamin-rich, low-calorie food. (A typical sushi meal of seven to nine pieces has 300 calories.) The fish used to make it - fatty tuna, sea bream, shrimp and squid - is full of nutrients. Among the vitamins commonly found in sushi are A, B1, B2, niacin and, sometimes, D.
Tuna has fish oil, which is used to prevent heart disease. Eel (as the Irish traditionally knew) is a source of iron. Nori seaweed - the black "paper" that holds the roll in norimake - has protein and high contents of vitamins A, B1, B2, B6, niacin and C. The rice vinegar added to sushi has antibacterial properties, prevents fatigue and lessens the risk of arteriosclerosis and high blood pressure, according to The Book of Sushi, by Kinjiro Omae and Yuzuru Tachibana. Ginger, which is served with sushi, is revered in Tokyo's Shinto shrines because of its capacity, legend has it, to neutralise certain poisons.
The sushi ingredients - ginger, soy sauce, vinegar and wasabi - were used in Japan for centuries to treat cholera, dysentery and typhoid.
Sushi is nothing without soy sauce, which is made from fermented soy beans. The two favourite aromas in the US are, in order, coffee and soysauce, according to one poll. Soy sauce, which should be translucent, was brought to Europe by Dutch seamen in the 16th century and was eaten in France during the reign of Louis XIV. Most recently, soy sauce has been included in the list of Weight Watchers' approved foods as a substitute for salt. Tamari is a gluten-free version, just as tasty.
As for the wasabi - or Japanese horseradish - it's full of vitamin C and has many times the antibacterial properties of ultraviolet rays. In ancient times it was used as an antiseptic. "It's so fashionable, that many Irish restaurants now have wasabi somewhere on the menu," says Glynn. Aya has even put it into mashed potatoes - that classic Irish dish.
So if Japanese food feels good, it's because it is good - and guilt-free - eating.