Green papaya salad, known in Thailand as som tam, is a salad of shredded unripe papaya tossed with a pounded dressing of fish sauce, lime juice, palm sugar, garlic, and chilies. It originated in the Isan region of northeastern Thailand and is now a staple of Thai cooking both at home and abroad.
The papaya is shredded or julienned fine so it readily absorbs the dressing, which balances sour, sweet, salty, and spicy flavors and is traditionally pounded together with a mortar and pestle. Variations add dried shrimp, peanuts, long beans, or tomatoes.
Similar salads appear across Southeast Asia under different names: tam mak hoong in Laos, sometimes made with fermented fish or crab, and bok l'hong in Cambodia, often with pickled vegetables. It's typically served with sticky rice and grilled meats as a counterpoint to richer dishes.