There was a stretch of time, several years ago, when a group of America’s Test Kitchen staffers made a monthly pilgrimage to FuLoon, a (now sadly shuttered) Sichuan restaurant in the Boston suburbs, after work. We’d settle in at a table, pour tea, and flip through the huge menu to strategize our order. Inevitably, a double order of suan la bai cai was on the list.
The napa cabbage stir-fry, prepared in the sour-hot style (“suan” means sour; “la,” spicy) that is iconic in Sichuan and northern Chinese cuisines, was the most unassuming part of the spread but would disappear almost as soon as it hit the table. Its combination of malty black vinegar backlit with aromatics, savory sweetness, wok hei, and dried chile heat was beguiling. The glossy sauce was spare and light, clinging just enough to the cabbage’s crunchy ribs and wilted leaves. When the vegetable itself was gone, we’d take turns spooning what was left of the glazy liquid over rice.
“This dish is so popular,” Maggie Zhu said when I spoke with the New York–based blogger behind Omnivore’s Cookbook and author of Chinese Homestyle: Everyday Plant-Based Recipes for Takeout, Dim Sum, Noodles, and More (2022). She talked about the sour-hot-sweet balance of the sauce; the aroma of the oil, infused with garlic, ginger, and scallions; the fragrance and subtle heat of the chiles; the twinge of char that the cabbage picks up when it’s stir-fried over high heat, and the vegetable’s textural dichotomy.
“The white part is smooth and really crisp, and the leaf part grabs the sauce really well and is extra flavorful,” she said.
The Sour, Slightly Spicy Side of Sichuan
The merger of sour and spicy flavors is canonical in parts of China, particularly Sichuan province. One of the cuisine’s 23 official flavors, suan la wèi (literally “sour and hot flavor,” but commonly phrased in English as “hot and sour”) combines malty black Zhenjiang aromatic vinegar (also called Chinkiang vinegar) and/or fermented vegetables with heat supplied by dried chiles, chile oil, or white pepper. Its profile, which skews more acidic than hot and tends to be balanced by salty and sweet elements such as soy sauce and sugar, is the crux of preparations such as suan la bai cai (sour and hot napa cabbage); suan la tang (sour and hot soup); and the aromatic dressing that’s drizzled over suan la chaoshou, Sichuan’s meat-filled wontons. In fact, its pungency and heat are considered salubrious for Sichuan’s climate: a source of warmth during the cold season and a trigger to sweat out the region’s dampness during humid summer months.
Play the Angle
The two-part nature of napa cabbage is particularly important to keep in mind when prepping and stir-frying, since the goal is for both components to cook quickly and evenly. That way, the vegetable retains its crunch and won’t kick off much of its abundant water and dilute the glazy sauce.
Simple, deliberate knife work and brisk, staggered cooking are all it takes: First, you separate the stiff ribs from the tender part of the leaves. Then, Zhu explained, the idea is to slice the ribs on an angle instead of simply chopping them.
The King of Vegetables
It’s impossible to convey the magnitude of napa cabbage’s role in East Asian cuisines, but consider this: The ruffled, oblong head, a cool-weather brassica that likely evolved as a cross between bok choy and turnip, has been cultivated in China for about 1,000 years. Nowadays, it’s a staple crop throughout Asia, where it has sustained populations through cold seasons and grows so abundantly that annual harvest estimates exceed 50 megatons. Truckloads of it line markets, where shoppers seek out the leaves’ mellow, sweet flavor and juicy crunch for everything from stir-fries and stews to slaws and dumpling fillings; and of course for fermenting to make kimchi, suancai, and other pickles.
Look for heads that feel dense and heavy for their size. The stems should be firm and sturdy; the leaves, tightly packed, light green or yellow, and mostly free of blemishes.
Wrapped in plastic wrap or sealed in a zipper-lock bag and refrigerated, the cabbage will keep for at least a week.
After discarding any outer leaves that are bruised or torn, peel away as many leaves as you need. (This is better than cutting into the cabbage, which will damage its cells and cause it to deteriorate more quickly.) If there’s dirt, rinse or briefly soak the leaves in cold water and then dry thoroughly.
Angle-Cutting Napa Cabbage
When prepping napa cabbage for suan la bai cai, be sure to cut the thick white ribs at an acute (roughly 45-degree) angle. Doing so creates more surface on which the sauce can settle and exposes as much of their capillary structure as possible (think: cutting fresh flower stems on a bias to increase water uptake) so that it soaks up sauce. It also thins the ribs so that they cook through quickly and evenly.
“You have to cut in a way that exposes more of the cut sides so it absorbs more sauce,” she said.
I didn’t appreciate how effective that subtle technique is until I compared two batches: one stir-fried with angle-cut cabbage; the other, with ribs that I’d conventionally chopped perpendicular to my counter. Thanks to their exposed capillary structure, the angle-cut pieces visibly gripped the sauce; the straight-cut cabbage looked and tasted barely coated.
From there, it was all about the order of operations—and speed. I flashed the aromatics and chiles in a couple tablespoons of vegetable oil until their fragrance wafted up from the wok, then cranked the heat to high and added the bias-cut ribs. Within a minute or two their edges started to turn translucent, which signaled me to add the chopped greens. A minute or so after that, they were on the verge of collapsing. Time to add the sauce.
On a Sour Note
“The tricky part is finding balance,” Zhu said as we were talking about the seasoning components. “It has to be the right amount of sour, sweet, and savory.”
Usually, that sourness comes from black Zhenjiang aromatic vinegar, one of China’s big four regional vinegars, which has been produced in the country’s eponymous eastern city for at least 1,400 years. There’s no tang quite like it—savory and punchy, with tangible sweetness and hints of smoke—so I made sure to add just enough soy sauce, oyster sauce, and sugar to support the acidity without obscuring it. A little cornstarch helped tighten everything up.
Now I make suan la bai cai all the time. It might be the fastest, most economical stir-fry I can get on the table. And when the rest of the meal is over, I can usually be found spooning the sauce over one last scoop of rice.