To add spice to a refreshing drink or stew, think kokum
A whole kokum fruit should be added at the beginning of a long-simmered dish such as dals, soups and stews; the spice has a tart, fruity and acidic flavour
Kokum (also spelled kokam) is the "round purple fruit the size of a small orange" produced by the Garcinia indica tree, according to The Oxford Companion to Food. But unless you visit the parts of India where it grows, you're unlikely to see fresh specimens.
Elsewhere, you'll find the dried version - either as a shrivelled whole fruit or ground into a coarse powder. It has a tart, fruity and acidic flavour, and cooling qualities, and is often used to make drinks. It's also used medicinally to treat inflammation, digestive problems and allergies.
The site advises using kokum for "dals, soups, vegetable and fish stews, and other liquid-heavy dishes", adding that one whole fruit should be added at the beginning of a long-simmered dish, "to impart a lovely fruity, herbal and sour flavour".
