Wash both dals well. Cover dals with an inch of water and let them soak for 2-3 hours.
Pressure cook dals with asafoetida, for 20 minutes. Cool, whisk well and keep aside. Alternatively, bring dals to boil, cover and simmer for an hour or till mushy. Stir often.
Chop onion and tomato finely.
Chop garlic and chile finely.
Heat oil in a pan.
Add onion. Saute till golden brown.
Drop garlic, ginger, chile, curry leaves and 3 tablespoons of cilantro and saute on a high flame for 5 minutes..
Add tomato, turmeric, chile powder, garam masala and cooked dal to onions. Stir well.
Season with salt.
Lower flame and simmer dal for another 5 minutes.
Pour lime juice over dal and stir to mix.
Garnish with remaining cilantro and pair with roti or rice.