In the mixing bowl soak the dal for an hour, after take Pressure cooker add soaked n drained arhar dal , turmeric, little oil , chopped tomato and 2.1/2 cup water mix well. pressure cook for 4 whistles.
After take the cooked dal mixture and mash it well with help of masher.
In a kadai, heat the oil add mustard, Cumin seeds, hing, Ginger garlic paste, and Curry leaves saute well and allow to splutter them.
Now add chopped Onion Saute until they turns translucent.
Next add cooked and mashed dal mixture mix well.
Additionally add all masala ingredients like chilli powder, Coriander powder, garam masala, sambar powder and salt according to taste then stir well.
Cover and boil for 2 mins on low to medium flame.
Additionally add chopped coriander leaves mix well.
Enjoy the toor dal sambar with Rice or roti...
