Dal rasam(Pappu rasam)

(Tamil: ரச‌ம்,Rasam; Kannada: Saaru; Telugu: Chaaru) is a South Indian soup. It is prepared mainly with the juices of tamarind or tomato with pepper and other spices. Lentils are added frequently and other vegetables optionally. It is eaten mixed with rice, or drunk by itself. In a formal meal, it is followed by the sambar course and is in turn followed by curd rice. It differs from sambar in that it usually relies on tomatoes for its sourness rather than tamarind, and it is usually much thinner. Rasam contains many spices which are considered beneficial to health.

The rasam above in the picture is one of the recipes from my motherinlaw.
It is made using the excess water from the cooked dal.
You cannt make this type of rasam by using the water from other dal varieties .
You make this type of rasam using the excess water from just two dals made with green leafy vegetables like spinach or Chinese Spinach(Thotakura).
It is very healthy for kids .Easy to prepare and you can feed infants because it doesnt contain any spicy stuff in it.It contain lots of vitamins and protiens which are essential for infants.
Ingredients and recipe is same as in the spinach dal which you refer in my dal section.You just need to add more water(instead of 3 cups you need to add 4 cups of water) to the lentils.If you can cook in a big vessel than in a cooker it would be much better and much tastier.
For tadaka or poppu you need to add the same ingredients.
Garnish with coriander leaves.
Goes on well with hot ghee rice.