Steamed, ground mung beans

At my house, when the batter hits the hot skillet and makes the “sssssee-oh” sizzling sound, everyone stops and waits for the banh xeo.

Hot from the pan and fragrant from a touch of coconut milk, the crispy-chewy Vietnamese crepe -- filled with pork, shrimp, straw mushrooms and mung beans -- is delivered on a dinner plate. Chopsticks are abandoned for kitchen scissors.

The large, folded-over crepe is cut into manageable portions. A section is placed into a palm-size piece of soft lettuce, and in go some cucumber slices and a few herb leaves. Fingers bundle up the package, then dunk it into a bowl of fish sauce spiked with lime, garlic and chile.

For years I reveled with the rest of my family in our homemade banh xeo (sizzling crepe). Just the onomatopoeia -- of the batter hitting the pan -- was enough to make me forget all my other favorite foods. But last year on my first trip back to Vietnam, I experienced true sizzling crepe enlightenment.

At a market stall in Hoi An, a lovely historic town in central Vietnam, a banh xeo vendor was turning out crepes that were fantastic -- far superior to the versions I’d prepared or eaten stateside. What was the difference?

And so I began a banh xeo odyssey which led me from stalls in Vietnam to my own kitchen, where I finally unearthed a traditional and better way of cooking banh xeo. The secret, I discovered, is in the batter.

In Vietnam, banh xeo are typically made by professional cooks who specialize in crepes with perfect chewy-crisp textures. Those of us making banh xeo in the U.S. often rely on purchased mixes, made chiefly of rice flour, turmeric and cornstarch. The mix-made banh xeo seldom reach perfect crisp-chewiness and soften so quickly you have to rush to eat them.

The crepes I tasted in Hoi An were made to order. Nearly translucent (not opaque like the mix version), they were crispy in texture and toasty in flavor, with an alluring chewiness, like that of perfectly cooked rice.

When each was done, the vendor individually wrapped it in a piece of rice paper -- some purists claim this to be the ultimate way of eating a crepe -- and proudly handed it over.

While I savored her crepe, the vendor asked, “Sister, how is banh xeo made in America?”

I told her about the mixes, but she looked at me quizzically, and I thought my language skills had failed.

“Oh, I bet they make them big, like the ones in the south,” she said, referring to the big, flamboyant, bright yellow crepes made in Saigon (at Vietnamese restaurants in the States, sizzling crepes are often called “Saigon crepes”).

I realized that she understood my words, but couldn’t fathom why a packaged mix would be needed for banh xeo. It was an alien concept.

But this wasn’t just a matter of mixes. Back home I looked for clues on how to make great crepes in cookbooks published in the U.S. and Vietnam. All called for a batter made with rice flour. Through experimentation, I realized that rice-flour batter -- whether it comes from a mix or is concocted from scratch -- produces crepes that quickly lose their crispness. Using extra oil and/or batter during cooking helps, but the crepes may end up greasy or thick.

Rice-flour crepes may also crack at the spine when folded over. Adding an egg, milk or extra coconut milk enriches the batter with fat, but the resulting crepes can lack the crunch that makes them fun to eat.

I fooled around with the idea that the fillings may affect the texture, but varying the pork or kind of mung beans did nothing to the crepe’s texture.

I picked up the phone and called Mom.

“I bet they [the pros in Vietnam] grind their own rice with a stone wheel,” she said, zeroing in on the rice flour itself. “You can try it with a blender,” she suggested, but added, “Why bother? The mix isn’t bad.”

Of course the mix isn’t bad, but neither is it great. How could she, a proud and excellent cook, flagrantly disregard tradition? It was as though she’d thrown down a gauntlet.

Over the course of a week, I soaked and ground raw rice for several batches of batter. Surprisingly, grinding rice wasn’t difficult because the soaking softens the grains nicely. And my blender emulsified the batter to a marvelous silky consistency.

Still, no luck. My crepes were disappointing compared with those I’d had in Vietnam, and they weren’t much better than the rice-flour versions. I went back to the books. In a book on southern Vietnamese cooking that I’d bought in Saigon, I found what I was looking for.

“A delicious banh xeo must be crisp at the edge,” the authors wrote. “The secret, perhaps, is that during the grinding of the batter, some cooked rice and cooked mung beans are added to yield fragrance, flavor and the ideal chewy crunchy texture.”

Bingo. There it was. Starchy foods like rice and beans soften and thicken during cooking, so boosting the raw rice batter should give the crepe chewiness. And, like the bottom crust of paella, the riceand the beans would crisp up in the hot oil and contribute crunch.

There’s usually leftover rice in a Viet kitchen and cooked mung bean is a common filling ingredient. The concept was ingenious and convenient.

All I had to do was figure out how much cooked rice and mung beans to add to the ground rice of the batter. After a few delicious rounds of experimentation (the crepes always tasted good but I was going for texture), I got the right proportion to send the batter over the top.

What did it? A couple of tablespoons of cooked rice and a tablespoon of mung beans.

The results? Fabulous -- just like the ones in Vietnam.