Drain the soaked Chanan dal and add to a pressure cooker along with 3 cups of water and turmeric powder.
Pressure cook for 8 minutes and then allow the pressure to release on its own.
Open the lid, give a stir or two. Keep aside.
Meanwhile, heat oil in a frying pan and add garlic cloves and cumin seeds. Fry until light golden. Add onions and fry again until they start to change color.
Add tomatoes, green chilies, ginger, salt, red chili powder, turmeric powder, garam masala, coriander powder and mango powder.
Add 1/4 cup of water, cover and cook until the tomatoes are soft and oil separates from the gravy.
Add the tomato gravy to the dal chana, mix, cover and allow to cook on low heat for 5-10 minutes until the dal is soft.
Garnish with fresh coriander and serve with boiled rice or roti.