Peel the skin and deseed the yellow cucumber. Wash and cut the cucumber into medium pieces. Keep aside.
Take a deep bottomed pan, add the red gram and fry till the raw smell goes.
Add water to the lentils, green chillies and cook till they are half cooked.
Add the cucumber to the lentils along with salt. Cook until lentils are done and cucumber is soft and cooked.
Mash the lentils and cucumber little bit, so you can see bit of cucumber.
Add the tamarind paste, turmeric, red chilli powder and mix well. Cook till the tamarind paste is well done.
For seasoning, take a pan. Add oil, split black gram, mustard seeds. Fry till they sputter.
Add dried red chillies, asafoetida and curry leaves. Pour it over the lentils.
Serve hot with rice or roti.