To prepare vegetable sambar, clean, wash and soak dal in water for 15 minutes. While the dal is soaked, clean and chop the vegetables (bottle gourd, tomato, carrot, drumstick).
Transfer dal to a pressure cooker with the chopped carrot, pumpkin, bottle gourd, tomato, turmeric powder, red chilli powder, garlic, salt and water. Stir to mix. Pressure Cook for 3 whistles over medium heat. The dal should become soft and mushy.
Turn off the heat and release the steam manually from the pressure cooker.
Heat ghee in a kadhai. Once hot, add mustard seeds, red chillies, asafoetida, and curry leaves. Saute for 30 to 40 seconds or till seeds start spluttering.
Add onion (shallots) and drumsticks. Fry till onions are translucent and drumsticks are tender. Add boiled sambar over the tadka (be cautious as there will be sizzling). Stir to combine.
Add tamarind paste, jaggery, and sambar powder. Allow the vegetable sambar to simmer over low heat for 15 minutes. Keep stirring at regular intervals. At this stage, you can taste and add more seasoning or spices to your sambar.
Serve Vegetable Sambar warm with idli, dosa or rice.