Wash the tur dal 2-3 times in water. Wash and soak the drumstick leaves / moringa leaves in a large bowl of water. Swish it around and allow any dust / dirt to settle at the bottom. Fish out the leaves and repeat process twice to ensure all leaves are clean. Remove any woody stems.
In a small (3 Litre) pressure pan or pressure cooker, place the washed dal, moringa leaves, halved tomato, turmeric powder and 2 cups water. Bring this to a boil. Cover with lid + weight (whistle). After 2 whistles, reduce flame / heat to minimum and allow to cook for 10-12 minutes.
Meanwhile, prepare the tempering for the Moringa Dal. In a small pan or a tempering ladle, heat ghee. Add asafoetida, mustard and cumin seeds, grated garlic, ginger. Once mustard seeds pop, add the spice powders, salt, jaggery and stir to combine.
Open the pressure cooker, mash the dal-moringa leaves with the back of the ladle, add the tempering to it and bring to a simmer.
Remove into a serving bowl and then add a squeeze of lemon.