Chaat masala is the tangy, savoury finishing blend of South Asian street food — a powdered mix built on sour amchur (dried green-mango powder) and sulphurous kala namak (black salt), rounded out with roasted cumin, coriander, black pepper, ginger and a pinch of asafoetida. Sour, salty and faintly egg-like, it is dusted over fruit, fried snacks, salads, drinks and chaat dishes rather than cooked into them.