Vegetarian, vegan, halal and other diets on the street

The problem for vegetarians is rarely visible meat. It is the seasoning. Ask about these even when a dish looks vegetable-only:

• Fish sauce (nuoc mam). Made from fermented anchovies and other fish with salt, and used in most dipping sauces, marinades and many broths. It is not vegetarian.
• Shrimp paste (mam tom) and dried shrimp. In bun bo Hue broth, in northern dips, and as the floss on banh beo.
• Meat or bone stock. Noodle soups that are served without meat may still use a pork or beef broth.
• Lard and pork crackling. Fried shallots in lard, crackling on banh beo in Da Nang and Hoi An, lard on com tam.
• Egg and dairy, for vegans. Egg in fried rice, pancakes and mayonnaise; condensed milk in coffee and many sweet drinks.

The standard banh beo, for example, contains dried shrimp and fish sauce; some stalls make banh beo chay, but you must ask. Soy sauce is the usual vegetarian substitute for fish sauce, although the two taste very different.

• Dedicated chay eateries. The easiest option. Many serve a buffet or glass case of tofu, mock meat, vegetables and rice; point and pay by the plate. Ask about egg if you are vegan.
• Rice stalls. Choose stir-fried greens, tofu in tomato sauce and plain rice, and ask for no fish sauce on the vegetables.
• Banh mi carts. Some make an egg banh mi or a vegetable one; ask them to leave out the pate and to use soy sauce only if it is plain.
• Market food halls. More choice than a single stall, and sweet soups (che) of beans, jelly and coconut are often plant-based; ask about condensed milk.
• Lunar days. On the first and fifteenth of the lunar month more chay food is on sale, including at temples.

Strict vegans should expect to rely on chay eateries and to ask a lot of questions elsewhere. Cross-contact with fish sauce and shared pans is normal at ordinary stalls, and nobody can promise otherwise.

Rice is the base of most street food, which helps: pho, bun, com tam and banh xeo batter are made from rice. The wheat comes in through banh mi bread, the fried dough sticks served with Hanoi pho, soy sauce, hoisin and some marinades. People with coeliac disease face the same cross-contact problem as allergy sufferers, because woks and oil are shared.

For low-sugar diets, note that southern cooking uses more sugar, and that dipping sauces, marinades and drinks are often sweet. For low-salt diets, broths and fish sauce are the main sources; ask for less sauce rather than none.