Tomato Dal Soup

Ingredients

• 0.5 teaspoon asafetida powder 
• 1.5 teaspoons mustard seeds black
• 5 servings cilantro sprigs fresh
• 5 tablespoons picked-over skinned toovar dal split yellow (a variety of pigeon pea, usually descibed as as lentils)
• 2 tablespoons ginger fresh peeled finely chopped
• 1.5 tablespoons ghee 
• 1 teaspoon ground coriander 
• 0.5 teaspoon ground cumin 
• 1.5 pounds plum tomatoes seeded chopped
• 1  chile such as serrano fresh red hot halved lengthwise
• 3  chiles such as serrano fresh green hot halved lengthwise
• 1 teaspoon tamarind concentrate 
• 0.8 teaspoon turmeric 
• 4 cups water 

Equipment

• sauce pan
• sieve

Directions

1. Wash dal in several changes of water until water runs clear and drain well in a sieve. Cook dal at a bare simmer in 1 1/2 cups water in a 3-quart saucepan until most of water is evaporated and dal has consistency of a paste, 40 to 45 minutes, stirring frequently during last 15 minutes to prevent scorching.
2. Heat ghee in a 6-quart heavy saucepan over moderately high heat until hot but not smoking, then cook mustard seeds and red chile, stirring, until seeds begin to pop.
3. Add 1 1/2 cups water and remaining ingredients (but not dal paste). Bring to a boil and simmer, stirring occasionally, until tomatoes are softened, 6 to 8 minutes.
4. Add dal paste and remaining cup water, stirring to incorporate. Bring rasam to a boil, stirring occasionally, and season with salt.
5. · Rasam may be made 2 days ahead and chilled, covered.
6. Add water to thin, if necessary, before reheating.