Add dal to a bowl and rinse it well at least thrice. Drain the water. If you don't have a pressure cooker, you may soak them for 30 to 45 mins so they cook faster in a pot.
Pour ghee or oil to a pot or pressure cooker and heat it. Add cumin, ginger, garlic, green chilli and curry leaves.
Saute until ginger garlic begins to smell good. Turn down the flame to low. Then add red chilli powder, turmeric, pumpkin and tomatoes.
Saute for 1 to 2 mins and add dal. Pour water and deglaze the pot.
Stovetop Pressure cooker - Cover the pressure cooker. Pressure cook on a medium heat until you hear 3 whistles. When the pressure drops, open the lid.
Instant pot - Secure the Instant pot with the lid and position the steam release valve to sealing. Set the timer to 11 mins. When the pressure drops, open the lid.
Regular sauce pot - Bring the water to a boil and simmer. Let the lentils cook slowly until done and tender. If required add more hot water as you cook them.
When the lentils are tender and fully done, add garam masala, kasuri methi and jaggery. Mix well, taste test and adjust salt. (if using spinach, cook further until the spinach is tender)
Turn off the heat and let cool down slightly. Then add coriander leaves and lemon juice.
Serve dal pumpkin with rice, roti, quinoa or naan.