Indian
Toast the cumin seeds in a dry pan over medium heat for 1-2 minutes until fragrant and a shade darker, then crush them to a powder.
Grate the cucumber on the coarse side of a grater and gently squeeze out a little of the juice by hand.
Whisk the yogurt in a bowl for 30 seconds until smooth.
Stir in the cucumber and most of the roasted cumin.
Mix in the mint and coriander, keeping a few leaves for the top, and chill for 15 minutes.
Just before serving, stir in the salt, sprinkle with the remaining cumin and the chili powder and serve cold with biryani, pulao, parathas or curries.