Last spring I had an interesting experience at a Japanese restaurant in Nyack, New York. I looked at the menu, and there was no Korean food listed. Boston has so many sushi bars owned by Korean-Americans that I had a hard time remembering the last one I’d reviewed that was owned by Japanese-Americans. Probably Oishii or Tsunami.

I don’t have a problem with this, and apparently most of you don’t either — Japanese-Korean storefront restaurants are successfully competing with Greek-owned pizza places and Chinese-American take-out joints all over Greater Boston. Non-Asian customers have developed a taste for this kind of food, and Korean-American entrepreneurs have provided it at a good level of quality and at a moderate price. As in all mass-market situations, the menu has become rather standardized, so how does a critic differentiate among these restaurants? Well, there are quality issues in sushi, such as how it’s cut, its freshness, and especially the quality of the rice. Although the non-sushi Japanese food is the most standardized part of the menu, some places fry better tempura than others, put more authentic vegetables in better stock in the noodle soups, or have a nicer touch with the teriyaki dishes. The quality of the Korean food also varies a lot.

Zen 320 moved into the space formerly occupied by Sawasdee, an unusually good Thai restaurant of that second generation of Boston Thai restaurants. Zen 320 isn’t at that level, but it’s a very competent restaurant of its type. And no restaurant that lists "pan-fried chicken intestines" as a side dish on its take-out menu can be ignored.

Although we didn’t try the intestines, our best appetizer was a chef’s special called "Dynamite" ($6.50). This turns out to be a little aluminum-foil rectangle full of sushi-quality seafood, grilled with a spicy mayonnaise — very good eating. I especially enjoyed the surf-clam slices, which are a difficult sushi, but with a little grilling provide plenty of chew so you can savor the mayonnaise.

The "Zen 320 salad" ($6.50), another good idea, combines the popular seaweed salad with some lettuce and a slice each of raw tuna, salmon, and fluke, plus a couple of pieces of false crab leg, all under the gingery dressing of typical Japanese salads. So you have a variety of flavors to mix and match, and won’t miss anything if you choose a simple entrée.

On the Korean side, the pa-jon seafood pancake ($9.95) is somewhat less eggy and more starchy than some I’ve had; this makes it work better if you want to eat it like a pizza, which it resembles. All the seafood in mine was squid, so what you have is an excellent scallion pancake with the additional flavors of fried squid and fried peppers. At about 10 inches in diameter, this is too large an appetizer for fewer than about four people, however.

More conventional items I sampled included a typically good oshitashi ($3.50), a spinach-sesame side dish; a fine white miso soup ($1.50); and an order of edamame ($3.50), green soybeans in the shell with coarse salt. You’re supposed to work the beans out of the shells in your mouth, thus absorbing the salt, and discard the hairy pods. I suspect most restaurant edamame come frozen, like the ones at my house, but these were badly thawed or reheated, so some were mushy and cold. The others were very good; green soybeans have a much more intense flavor than lima beans.

My favorite entrée was salmon teriyaki ($9.95). This is really an American development, but if you get the right sauce and don’t over-broil the fish, it is one of the best possible treatments for our fat, farmed salmon, and that’s the case at Zen 320. The sautéed mixed vegetables on the side — broccoli, carrots, onions, and peppers — weren’t as crunchy as the ones at Jae’s, but worked well with the salmon here.

I also liked the version of spicy squid ($11.95), a common Korean dish on this kind of menu, here soupier than some, the better to spoon onto a bowl of rice, and about two-asterisks hot. The squid was not overdone, and again there was a mix of vegetables, mostly onions, but also some broccoli florets, red and green bell peppers, and carrot. The rice, I have to say, was not overly aromatic, just slightly sticky medium-grain rice.

Rice was a more serious problem with some of the sushi. If you’ve ever tried to make sushi at home, you know how fussy the rice preparation is. If it isn’t cooked properly, your inside-out rolls fall apart when dipped in a little soy sauce. (I’ve read that you’re not actually supposed to dip the rice part of the sushi into soy sauce, only the fish. But if the chef makes an inside-out roll, with the fish and seaweed wrapper inside, what else can you do?) One of our party made her own sushi assortment out of orders of yellowtail ($3.95), salmon ($3.75), mackerel ($3.95), "combo veggie roll" ($4.50), and tekka roll ($3.95). The fish were all excellent, but the first three nigiri-style sushi and the inside-out rolls were somewhat crumbly in the rice department. This wouldn’t usually be a problem with tekka maki (tuna rolled up in rice with a seaweed wrapper), since it usually isn’t done inside out. The name apparently means "gambler’s roll," as this was a quick snack in a gambling den. Because your hands didn’t touch fish or rice, they didn’t have to be washed between deals.

I am lazy with menus, and simply went to the sashimi deluxe ($19.95), which is straight raw fish served on a boat. The assortment was five slices of dark tuna, five of salmon, six of a white fish, three of mackerel (almost always a cooked sashimi), three of a meaty fish like king mackerel, and three of cooked octopus. All the fish was excellent, even the often-fishy mackerel, but the cutting was not brilliant. I also missed the leaves of shiso, a green herb of intense flavor usually served with sashimi, although there was plenty of wasabi and pickled ginger.

If you are eating alone, the bento boxes ($10.95–$11.95) make a nice option. These are typically lunches, but Zen 320 now also serves them at dinner. The restaurant has wine and an assortment of beer, including Japanese and Korean offerings. Drinks also include seven cold sakes and one served hot.

The space is a narrow L shape with the long side in the back. It was never large, and the back dining room still seems kind of unfinished. Its real drawback, however, is overly loud, poorly chosen pop party music. This is Brookline, a suburb where people move to send their children to the good schools, so most of the customers go out to a restaurant to escape this kind of music, typically blared by the elementary- and middle-school children. High-school kids in Brookline go out to restaurants, and some of them like sushi, but they don’t like this kind of music either — it’s what they’ve just outgrown.

Robert Nadeau can be reached at RobtNadeau@aol.com