Mix flour, sooji, baking powder, and salt in a mixing bowl. Add milk and stir to make a soft dough. Add more milk or flour, depending on if dough is too thin or too stiff.
Wash both dals together. Add 2 cups water, a pinch of turmeric and cook dal in pressure cooker 1 whistle and low heat for about 15 min;let pressure release naturally.
Mix 1/2 tbs Garam masala, 1 tsp Red chilli powder, 1/4 tsp Haldi (turmeric) powder, 1/4 tsp Dhania pwdr(coriander)in 1/2 cup water to make thin paste. Put ghee in a pan and heat.
Splutter 1 tsp cumin seeds, 1/2 tsp mustard seeds, & 1/4 tsp coriander seeds. Add ginger and the paste of spice powders. Fry for a minute, then mix it into the dal. Add 2 cups of water, salt and stir well. Drop dumpling dough into dal and simmer for 15 minutes without removing cover. Add lemon juice. Garnish with chopped coriander & serve.