First presurre cook the Bengal Gram till it is properly cooked. Thinly slice onion. Heat a pan with some oil and add onion along with thinly sliced garlic cloves and stir well.

Cook till onion is almost brown. Now add chilly powder, coriander powder,  salt and garam masala. Mix it well with the onion for 2 minutes.

Add tomato and cook for 4 minutes till tomato is little mushy. Now let it cool for sometime. After that grind this onion tomato mixture in a mixie.

Now add the grinded mixture to the pan and when it boils, add the cooked bengal gram to it. Add water as required. Check for salt.

Lastly season the curry with mustard seeds and red chilly.