Heat a pan and add ghee or oil to it. Add makhana to the pan and roast them till they become crisp. Once they become crisp, keep them aside and let them cool down.
Now take curd in a bowl and whisk it to get a smooth consistency.
Add chopped cucumber, green chili, cumin powder, and salt. Mix everything well and add roasted makhana. Serve immediately.
If required you can add little water to adjust the consistency of the raita.
Notes
Instead of green chili, you can add red chili powder or pepper powder or both as well.