Street food is a serious institution in Taiwan. Ask for a local's favorite snack and no sooner than perching down on tiny stool will you receive this jiggling specialty. Partially translucent from a sticky and somewhat mysterious goo binding fried egg and bits of oyster, and slick with a sweet-and-sour ketchup-based sauce, the Taiwanese oyster omelet is a memorable dish that has a fervent following.
Taiwanese oyster omelets (or "pancakes," as they're sometimes translated) have roots in Fujianese cuisine. They share some similarities with the Japanese okonomiyaki. But nowhere are they more adored than in Taiwan. Oysters are abundant on this island, and enjoyed in various preparations (mostly cooked). If you're a fan of the sweet, briney bivalves, or have appreciated a hangtown fry in your time, then here's a truly different way to experience oysters.
You'll need a good handle on flipping and a few simple ingredients to make this at home. Besides the eggs, oysters, starch-based slurry, and sauce, the other classic ingredient is some type of leafy greens. Some shredded bok choy or baby spinach will work, but I've seen celery leaves used, and think their distinctive, herbacious flavor complements the oysters well. If you're in a pinch, a handful of chopped scallions work nicely instead—or in addition.
For that clear, gelatinous binder, I made water-starch mixtures with three common starches in the Taiwanese pantry: tapioca starch, cornstarch, and sweet potato starch. Recipes and chefs seem to use one or the other to attain their preferred consistency. You'll spill this slurry into the pan shortly after introducing a lightly beaten egg to the oysters. It'll gel up, in irregular patches, forming a soft disc of alternating textures, especially when you factor in those of the oysters themselves. Then, place your leafy greens atop the eggs and swiftly flip over the whole omelet to cook the on opposite side for a few moments.
The tapioca starch test came first. The result was overly gooey, and absolutely unflippable. The streaks of cooked slurry were about the consistency of raw egg whites—unpleasant even as sure as I was that the eggs were cooked. The second trial, using cornstarch, came a bit closer to my vision. But it was still hard to flip the darn thing over intact. Finally, with sweet potato starch, the right balance was met: the clear parts were gummy, but still had some body rather than being a loose, slimy mess. If you prefer your omelet goopier, you could adjust by mixing in some tapioca or cornstarch to your potato starch slurry. But I liked mine—and flipped it—just as well with sweet potato starch alone.
A highlight of this dish is the tangy sauce that's poured liberally over the finished omelet. You'll need to make this ahead, but it's much less tricky than the omelet. It's based on ketchup, which is diluted in intensity while thickened by another starch slurry—in this case, cornstarch does the job fine. Some sugar, vinegar, and soy sauce enhance the flavor, and I've seen everything from Worcestershire sauce to peanut butter added in small doses for complexity. I eschewed both these for a dab of red miso paste instead, because I like the savory depth it lends.
When it's all said and done, the Taiwanese oyster omelet isn't really an omelet in any Western sensibility. Its attraction has as much to do with texture as it does flavor. Allow it to grow on you, and you might just find it irresistible.