This recipe is perfectly paired with steamed basmati rice, fresh roti, and Indian carrot pickles.
In a 2 quart pot melt butter over medium-low heat and add the chopped onion. Sweat for 10 minutes until the onion becomes soft, translucent and lightly browned. Add crushed garlic and cook for about 30 seconds.
Stir in turmeric and sliced chili, cook for another 30 seconds then add the dal. Stir to coat the dal in the seasoned onion mixture. Add four cups of water, stir and bring to a boil.
Once the dal has come to a full rolling boil add salt and sugar then reduce the heat to a slow simmer. Cover and cook for 25 minutes. Do not stir.
Uncover the dal and cook an additional 15 minutes. Do not stir.
After 15 minutes agitate the cooked dal by inserting a whisk in the center of the pot and gently roll it between your hands to create movement. Do this for about one minute to break up and thicken the dal.
To make the tadka, heat oil over medium-high heat until it begins to shimmer and smoke slightly. Add mustard and cumin seeds to the oil and cook until the seeds start to spatter and bust. About 30 seconds.
Add ginger and fresh curry leaves to the pan, stir for another 30 seconds. Stir in the tomatoes.
Pour tadka over hot dal and garnish with cilantro.