In a large non-stick pot, heat the oil on medium heat.
Add the black mustard seeds and asafetida and fry for a few seconds until fragrant.
Immediately add the garlic, onions, and green jalapeno chili. Saute until fragrant and the onions start to become translucent. Be sure not to burn the mixture. If you find this happening, either add some more oil or turn down the heat.
Add the cooked urad dal, cooked chana dal, turmeric powder, and salt. Saute with the onion-garlic mixture for a few minutes, mixing frequently.
Add the water and the bring the soup to a gentle simmer. Once simmering, turn down the heat to medium-low.
Continue to simmer on low heat until some of the water boils off and the soup becomes thick in consistency (about 10-20 min). If you start to feel the soup becoming too thick, you can add a little more water.
Add the chopped cilantro. If needed, season once more with salt to taste. Simmer for additional 3-5 minutes.
Garnish with some fresh cilantro and serve warm with roti, naan, or toasted french bread.
Notes
Urad Dal - These are black lentils (or urad dal) that have been split and skinned.Chana Dal - Chana Dal is also known as Split Bengal Gram. Be sure not to confuse it with Yellow split peas, as they are not the same. You can find this Dal at any local Indian market in bulk for cheap, or online. To Cook Dal - Combine both the Urad and Chana Dal in a bowl. Wash and soak in water for about 20-30 minutes. Drain the water and cook using one of two methods: (1) Pressure Cooker , or (2) Pot of boiling water. Cook the Dal until soft, but not mushy. Drain the water after cooking the dal.Asafetida (hing) - Although this powder is naturally gluten-free, it is almost always manufactured by diluting it significantly with wheat flour. There are some brands you can find that make it with rice flour. If you are uncertain and have a gluten-free diet, then you can easily omit this ingredient.