Bún mắm
Vạn Kiếp Street in Saigon's Bình Thạnh district is lined with stalls serving bún mắm, a noodle soup that came up the river from the Mekong Delta. The broth is built on mắm cá linh or mắm cá sặc, small river fish fermented with salt, simmered until the bones dissolve and strained into a dark, savoury, lemongrass-scented stock. It is loaded with prawns, squid, white fish, slices of boiled pork belly and soft aubergine, and eaten with a mountain of herbs and bean sprouts. Look for jars of mắm at Vietnamese grocers. Chef's tip: strain the fermented fish through a fine sieve, pressing hard; tiny bones make the broth gritty.



