Wash and peel the cucumber. Grate it on the coarse side of a box grater.

Place the grated cucumber in a clean kitchen towel or cheesecloth and squeeze out as much water as possible. This step is important — skipping it makes the raita watery within minutes.

Set aside.

Heat a small dry pan over medium heat. Add the cumin seeds.

Toast for 60–90 seconds, stirring constantly, until they turn a shade darker and smell nutty and fragrant. Watch carefully — they go from toasted to burnt quickly.

Remove from heat and let cool for 1 minute, then roughly crush with the back of a spoon or in a mortar and pestle.

In a mixing bowl, whisk the Greek yogurt until smooth. If it feels very thick, add 1–2 tablespoons of cold water and whisk again.

Add the squeezed cucumber, salt, black salt, roasted cumin powder, and chaat masala (if using). Stir to combine.

Fold in the chopped coriander and mint.

Taste and adjust salt.

Transfer to a serving bowl. Top with the toasted cumin seeds, a pinch of red chili powder, and a few mint sprigs.

Refrigerate for at least 15 minutes before serving — the flavors come together beautifully when cold.