The tables at Vien Dong are undersized for the amount of food they serve–$50 will blanket an entire four-top and leave platters of herbs and rice noodles precariously balanced above the main dishes. The tantalizing scent of chả cá Thăng Long, turmeric-marinated catfish grilled on hot iron with dill and onion, permeates the whole place. What you'll see next to it on most tables, though, is a northern Vietnamese speciality: shrimp and sweet potato fritters, or bánh tôm cổ ngư in Vietnamese.
It's a messy, brown, oily pile; it doesn't photograph well at all, but that doesn't matter. Somehow, this perfect marriage of shrimp and yam has escaped American eyes. The dish is barely contained on its platter; as you tear off pieces of food barely bound together with fried batter, you'll jettison just the right amount of herbs to wrap up the fried treat. And despite the fact that both shrimp and yams are sweet, they balance each other, though you'll want to add a dab of pickled chile paste before dunking your lettuce-and-yam burrito in the dipping sauce. It's enormously satisfying, and the portion is big enough for that four-top to share before diving into the grilled fish undoubtedly on order.
Incidentally, the shrimp shells are fried crispy so you can eat them; don't pick apart the dish or you'll end up with orange bits all over your shirt.