Bánh Xèo (Sizzling Vietnamese Crepes)

Before experimenting with the crepe batter, I sorted out the proteins. Pork belly, as much as I love it, isn’t always easy to come by. In its place, I opted for readily available, well-marbled country-style pork ribs. Rather than small shrimp, I chose (again, easier-to-find) medium-large shrimp that I cut into small pieces.

The batter for bánh xèo is made by whisking together rice flour, water, coconut milk, turmeric, and salt. In the best versions I’ve had, the crepe cooks up lacy at the edges, with a universe of variously sized holes within. And yet, my first few crepes failed to crisp and were marred by thick patches.

I soon realized that because the crepe set so quickly in the hot skillet, it was crucial for the batter to rapidly flow over the entire pan surface. If it didn’t spread fast enough, it gathered around the pork and shrimp, creating a crepe with both thick spots and gaping holes. I found that in order for the batter to flow freely, it needed to have a consistency comparable to heavy cream, which I achieved with 1 cup of water, 1⁄3 cup of coconut milk, and ½ cup of rice flour.

But a loose consistency and a thin crepe weren’t enough to ensure crispness. For that to happen, you must manage the fact that rice flour is slow to absorb water. This is a problem because in order for the crepe to dry out and crisp, any water in the mixture must first be absorbed by the starch in the rice flour to create a gel. Then the water must be driven off quickly, to leave behind disordered, rigid starch molecules with gaps between them—in other words, a crisp, lacy texture. If no gel is formed, the starch remains orderly when the water exits, without gaps and therefore without good crispness.

Using hot water didn’t help, though it did mitigate the slight grittiness by allowing the water to penetrate and hydrate the particles enough to soften them somewhat. Many recipes call for letting the batter rest before cooking, and I wondered if this would give the starch more time to absorb the water in the rice flour. But when I tried a rest, it had no effect.

I decided to follow the lead of a few recipes I found that called for incorporating a bit of cornstarch. Whereas rice flour is slow to hydrate because rice kernels are rather dense and the flour is not milled very fine, cornstarch is a pure starch that’s been treated with water and finely milled, so it readily soaks up moisture. Just 3 tablespoons helped ensure a crisp texture without noticeably thickening the batter.

Finally, I realized the importance of the sound the crepe made during cooking. If the pan wasn’t hot enough to say “xèo” when the batter was poured in, it formed a thick, soft skin. If instead it was hot enough to sizzle audibly, that was a signal that the water was rapidly being driven off to form the ideal cracklingly crisp, holey appearance.

At last, I was ready to hold my first bánh xèo party. I started by mixing up the Cook’s Illustrated recipe for nước chấm and preparing a batch of tangy đồ chua and divided them among small individual serving bowls. Next, the crepes: To serve four people at once, I kept the first few crepes warm on a rack in a low oven, which did not compromise their hard-won texture. I chose tender Boston lettuce for the wrappers, since its leaves are supple yet large enough to create a good-size bundle. Lastly, I set out generous piles of fresh cilantro and Thai basil leaves. It was time to feast.