Onion Sambar

Vengaya sambar is what my dad used to call this. This is a nice combination with Puri or Chappati. It can be prepared real quick.
Ingredients :
Gram Flour : 2 tbl spnsPotatoes : 2 Nos. (optional) Onions : 1 No. BigTomato : 1 No.  Green chillies : 3 Nos.Curry leaves : 1 string Mustard seeds : 1/2 tspnUrad Dhal : 1/2 tspnTurmeric : 1/4 tspnCumin pwdr : 1/2 tspnFennel seeds : 1/2 tspnSalt to taste Oil : 1 tbspnMethod of preparation :
Heat oil in a pan fry mustard seeds, urad dhal, fennel seeds, turmeric, green chillies and onions (chopped lengthwise) and fry when onions are almost done add tomatoes chopped  in big chunks In the meanwhile mix gram flour with some 2 cups of water in a bowl. Add this mixture into the fried onions along with salt and cumin powder. Add more water than the required thickness of the gravy as gram flour has to boil for 5 min during which it absorbs a lot of water. (Cooked potatoes to be added now)Do not add too much salt.  Cook for 5 min and serve hot with Poori or Chappati.Note : This got to be served when its hot. Tends to thicken when its cold.  Add a lot of water and it thickens as gram flour cooks. I tried this with rice also and it tasted good.
Also Known as : Bombay Chutney, Onion Sambar, Erulli Sambar, Potato Curry, Poori Potato Curry