Order the quail curry at this hip and gently priced London Vietnamese joint that can easily rival the best in Saigon. For $35 a head, the kitchen wows us with a Southeast Asian feast. First, the house specialty: “La Vong fish,” marinated in turmeric and galangal, grilled tableside with a flurry of dill, and served with rice noodles and peanuts. To follow, a salad of lotus stems, prawns, and crisp pork nuggets. Then a complex coconut quail curry, and lemongrass-scented mackerel baked in banana leaves.