The store takes less care than an American supermarket to put the most important items at eye level. There are also fewer highly visible corner displays and promotions, and the overall organization is more cluttered.

Then there's getting your cart down the aisle. The main aisles fit two carts side by side, barely. It's hard to get down the aisles, and that discourages browsing. My initial tendency was to search the empty aisles, if only because I knew I could get down them without much delay. This obviously isn't the best strategy, and it led me to spend too much time looking at the highly durable items, which are purchased less frequently by other customers. Overall, I felt far less mobile than in an American supermarket. I started going later at night and avoiding the weekends to circumvent these problems.

It's common to see a Great Wall customer spending a solid minute or two inspecting the quality of a pineapple, thereby blocking that portion of the aisle. The customers who seek green peas go through the bin pea by pea. One woman became entranced picking out the best garlic chives, and a man asked for sales help in selecting the best clams--by what standard he judged them I'm not sure. No one was much enamored of the scooping technique for filling a plastic bag.

So much for shopping. What about the contents of Great Wall?

The most striking difference, other than having lots of Chinese food, is how much of the store is devoted to greens. Once you push your cart through the door, those are the first things you see, and lots of them. They're fresh and cheap, and there's a more attractive selection than in any other area supermarket. The greens are the store's signature, and once you've tried them you know you'll always have reason to come back. Even the other local Chinese supermarkets don't compare. Great Wall deals with special farms in New Jersey, New Mexico, and Texas to keep the supply flowing.

The greens are also the store's "loss leader"--what brings in customers, who go on to buy higher-margin items. In an American grocery store, the loss leaders are likely to be staples such as milk or whichever sale items are advertised in the circular or on the Internet.

The greens at Great Wall include Chinese garlic chives, sweet-potato vines, baby Chinese broccoli, chrysanthemum greens, snow peas, green beans, baby red amaranth, yam tips, white shen choy tips, baby yo choy tips, and many others. Where else can you get six or more varieties of bok choy?

Most of the greens are in large piles, look very fresh, and are attended to frequently by staff . My dominant impression of the store is of seeing rows of endless greens, broadly similar in appearance, and not being sure which to buy. But they all turned out to be tasty and easy to cook, if only by steaming.

You also can find cabbage, broccoli, spinach, green peppers, kohlrabi, leeks, cauliflower, and squash, among other vegetables, so you don't have to give up American favorites. The quality of these items is also above average, and the prices are much lower.

The greens section is also the busiest part of the store. Often mainstream supermarkets put the most commonly bought items in corners or on the back wall (think dairy), to force long walks and thus to stimulate impulse purchases along the way. Great Wall puts the greens up front. Everyone comes in and stops to look around at them. The traffic jam starts right away.

Once I started shopping at Great Wall, I began to eat more greens, and to enjoy them more. I never had to tell myself they would ward off cancer, make the earth a better place, help me lose weight, or ease animal cruelty. I wanted to eat them, and the purchases felt virtually free of charge, given the low prices. I could try any new and unknown green without investing much money.

There wasn't much of a learning curve--I made this shift by my second or third visit of the experiment. If nothing else, I would steam some greens whenever I was making dumplings. Each time I visited, the main question was which green I'd try next and whether I could remember the ones I'd already sampled (often I couldn't). Each of these leaps into the dark was delicious; that I wasn't once disappointed is remarkable.

It was this kind of lopsided reward that got me thinking about the need for a new kind of food revolution and how it can be accomplished.

The nearby fruits were also good, although they can't compare to the greens. Great Wall has better-than-average grapes, standard American fruits at lower prices, and a touch of exotica, such as durian and rambutan when available.

The second notable section of Great Wall is the seafood, which has a far more extensive choice than would an American supermarket. One day I counted 51 bins for distinct seafood items, including crabs, clams, octopus, mussels, and fish. The seafood section is crammed to accommodate this variety, with fish tanks running both below the main counter and on the wall behind the workers.

Just about all of the space is used to store and present creatures living and dead. The impression is one of a cornucopia of items that are too bony, with too many scales, or too reeking of the sea to satisfy most American appetites.

I asked Rong Rong about the fish, and she expressed some disappointment, at least compared with China. She's used to live fish in tanks, and she didn't always find the displayed dead fish tasty when she cooked them.

At Great Wall, many of the fish need to be scaled. There are some filets, but most of the seafood is whole--bones, eyes, and all. I often prefer whole fish, especially if it's accompanied by a good sauce, but I know I'm the exception to the rule in this country.

It's a splendid section for constructing a seafood stock, but I never got the hang of how to convert the dozens of choices into easy-to-make, easy-to-eat meals. Bringing home a bunch of small whole mackerel made me long for the good canned product at Whole Foods. Eating a steamed small mackerel with chopsticks isn't much fun for me. I like the taste--it just feels like too much work.

Most of the shrimp are in their shells. The octopus and squid and mussels all look as if they were just pulled out of the ocean--tentacles and everything. Sometimes not-yet-dead fish have been pulled from the tank and flop around on the ice, but no one seems to notice.

The seafood section emits a strong smell. The scent serves as advertising to Chinese customers, but it puts off many non-Chinese patrons. My wife and stepdaughter object to this smell--one reason they don't like to accompany me to Great Wall. At first they'll cite pragmatic reasons why we shouldn't go, but if I continue the debate, sooner or later they come back to the smell.

In the online reviews at Yelp, the smell of the fish and meats comes in for repeated criticism from reviewers who, judging by the photos, appear to be non-Chinese. Personally, the smell never bothered me--I even found it a convenient navigational aid.

Great Wall was recently charged by authorities with "selling wildlife," which is illegal in Virginia. Store managers maintain that the bullfrogs, crayfish, swamp eels, and other items the store sells are farm-raised and should be exempt from the prohibition. If the legal questions aren't resolved in the store's favor, some of its vaunted diversity in seafood may be on the way out.