Market Bowl · Herbal Sour Soup

Tom Saep (Isaan Spicy Sour Soup)

Photo: Takeaway / Wikimedia Commons · CC BY-SA 3.0

Its name simply means 'delicious soup': saep is the everyday Isaan and Lao word for tasty.

Pork ribs or offal are simmered in a clear broth with lemongrass, galangal and kaffir lime leaves, then seasoned with lime juice, fish sauce, fresh and toasted dried chilies, and finished with a handful of fresh herbs such as sawtooth coriander and basil, producing a soup that's sour, salty and fiercely spicy all at once.

Why it's made this way: The soup shares the same Lao-Isaan culinary DNA as larb and som tam — a reliance on lime, fish sauce and fresh herbs over coconut milk or thick curry pastes — and is a staple at Isaan market food stalls alongside grilled meats.