Rinse the toor dal thoroughly until the water runs clear. Add it to a pressure cooker with 3 cups of water and turmeric powder. Cook for 4–5 whistles until soft and creamy. Mash the dal lightly once cooled, then set aside.
If using whole tamarind, soak it in warm water for 15 minutes, then squeeze out the pulp and strain. This extract adds the signature tanginess of traditional sambar.
In a large saucepan, add the chopped vegetables with 2 cups of water and a pinch of salt. Simmer until they are just tender but still hold their shape. Avoid overcooking to preserve texture.
Add the cooked dal to the simmering vegetables. Stir well to blend. If the mixture is too thick, add a little water to achieve a stew-like consistency.
Stir in the tamarind extract, sambar powder, and chopped tomato. Let it cook for 10–12 minutes on a medium flame until the raw aroma of tamarind fades and the flavours meld beautifully.
Taste and adjust salt or tamarind to your preference. The flavour should balance between tangy, spicy, and earthy. Continue simmering until a rich aroma develops.
In a small pan, heat sesame oil. Add mustard seeds and allow them to splutter. Stir in cumin seeds, dried red chillies, curry leaves, and a pinch of asafoetida. Fry briefly until fragrant, taking care not to burn the spices.
Pour the hot tempering into the simmering sambar and stir well. This step releases the full flavour of the spices into the stew, creating its signature aroma.
Let the sambar simmer gently for another 5 minutes after adding the tempering. This allows the spices to infuse completely into the lentil base.
Turn off the heat and sprinkle with fresh coriander leaves. Serve hot with steamed rice, dosa, or idli. A drizzle of ghee before serving enhances its aroma and flavour beautifully.