Wash dal and pressure cook till soft. Once the pressure is off, remove container of dal and churn it till it is smooth.
Dry roast all ingredients under Masala except grated coconut till lightly browned. Add 3-4 drops oil and stir. Turn off the gas. Add grated coconut and saute till it is lightly colored.
Cool and grind in mixie/food processor till fine powder is formed.
Soak tamarind in warm water for 5 minutes and squeeze out the pulp discarding the pith.
Take a deep pot and add dal to it. Add water according to sambar consistency (not too watery). Add the roasted masala to the dal and all the vegetables except drumbsticks. Boil drumbsticks separately.
Bring the dal to a boil. Cover and cook till vegetables are done. Add tamarind pulp and cook for some more time till tamarind flavor is blended in the dal.
Prepare the tempering--In another pan, heat oil. Add mustard sseeds, hing, red chilies, and curry leaves. Sauté. Add fenugreek seeds. Stir for few seconds and add the tempering to the dal.
Quickly place a lid as soon as the tempering is added to infuse flavors in the dal.
Keep simmering on very low heat for additional 10 minutes on low heat. Serve with rice, idli, dosa,uttapam, Medu vada, etc.