heat little oil in a pan and roast black sesame seeds until it pops. when it starts popping, take it in a plate.
in same pan, heat little oil and add chana dal and urad dal with skin. fry until it is reddish. take it to a plate and keep it aside.
Again in the same pan, heat little oil and roast red chillies, curry leaves and asafoetida powder. fry until they are crisp. take it to the plate and let it cool completely.
once it is cool completely, transfer to a mixer and add salt to it. grind to coarse powder. you can also grind to fine powder as per your preference.