Take 1 t.s oil in a pan add mustard seeds ,cumin,black lentil, and curry leaves.
Saute till seeds start crackling ,then add asafoetida and turmeric .
Add chopped tomatoes and salt, cover and cook till they become soft.
Now add chilli powder and sugar ,cook for a while.
Take out in a bowl and let it cool down completely.
Grind it in the mixer and make a smooth paste
Now add grated cucumber and beaten curd in the tomato paste
Mix well and add fresh chopped coriander.
Serve chilled .
Serving suggestions-can serve with pulao ,paratha, jeera rice or as a dip