If you are preparing fresh sambar masala, roast all the ingredients separately mentioned under 'to prepare masala' section in 1/2 tsp oil until they turn slight red in color. Once it gets cooled grind the ingredients to powder.
IWash and soak the rice and toor dal separately or together for 10-15 minutes. Pressure cook them together or separately. You should also make sure that the rice should not become lumpy.I usually add 3 - 3.5 cups water when pressure cooking both together.
Cut vegetables into 2" pieces.
Soak and squeeze tamarind pulp and dilute it with 1/2 cup of water then Add salt and turmeric powder and add cut vegetables and pressure cook it for 1 whistle.
Now Heat oil and ghee in a big kadai and crackle mustard seeds and add curry leaves, asafoetida and fry until they wilt.
Add cubed onions or shallots and fry it until they become translucent. Add chopped tomatoes and fry it until it becomes pulpy.
Now add cooked vegetables along with tamarind water and add turmeric powder, sambar powder, freshly ground powder, jaggery and bring it those to a boil. If you feel the water is less add another 1/2 cup of water now.
Add cooked dal and rice to it and mix it well and reduce the flame and let it cook for 7-8 minutes until it becomes thick and all the ingredients are blended well.
Liberally top it with ghee and serve it hot with Potato chips and Onion-Tomato Raita.