Tomato Sambar for Idli

This is one of the common combination thats made by my mom for Idli. It goes well with Rice also.
I have never tasted similar sambar else where like in hotel or at any friends place. Probably this is altered and changed to suite the taste of my family by mom. :)

Ingredients :
Tomato : 2 Nos. Onions : 1 Nos. Curry Leaves : 1 string Coriander leaves : for garnishing Mustard seeds : 1 tea spn Urad dhal : 1 tea spn Chilli powder : 1 tbl spoons Oil : 2 tbl spn Salt to tasteFor grinding :
Tomato : 1 No. Grated coconut : 6 tbl spns Fried grams : 4 tbl spns Fennel seeds : half tea spnMethod of preparation : 
Grind the ingredients mentioned for grinding and keep it aside. Add oil in a pan, add mustard seeds once it splutters add urad dhal and curry leaves. Now add onions and once it turn translucent Add tomato and fry it till the raw smell goes away completely. Now add the ground mixture along with enough water, chillipowder and salt. Boil this for around 10 minutes. Garnish with coriander leaves and serve with rice idlis / chappatis