1/4 cup tuvar dal (optional)
1 medium lime sized ball of tamarind
1/2 tsp turmeric powder
1 tsp salt to taste
3-4 tsp sesame oil
1 tsp mustard seeds
4-5 round, dried red chillies (long), halved
1/2 cup tuvar dal
1/4 tsp fenugreek seeds
1/2 tsp asafoetida powder
2 tbsp finely chopped coriander leaves
1. Wash dal (if used) and drain. Place dal in a pressure cooker with 1 cup water. Cook under pressure for 5 minutes.
2. Add 1 cup water to cooked dal, whisk well and set aside.
3. Soak tamarind in 3 cups water for 10 minutes. Extract juice and discard pulp.
4. Heat oil for tempering in a frying pan over low heat. Add remaining ingredients for tempering in the order given. When mustard seeds splutter and dal turns golden, mix in tamarind juice, turmeric powder and salt.
5. Bring to boil, lower heat and simmer for 40-45 minutes, stirring occasionally, till dal is cooked and soft.
6. Mix in cooked dal (if used) and simmer for about 5 minutes, till well blended.
7. Add more water if rasam is too thick.
8. Garnish with coriander leaves.
Serve hot with rice.
Note: Cooked dal is optional. Traditionally, it is not added. If you need the rasam thicker, then you can add.