Boil lentils with twice the water in an instant pot or pressure cooker. Mash it with a masher and keep it aside.
Heat oil in a saucepan. Add mustard seeds and let it splutter. Now, add chopped onions, ginger and let it sweat.
Add chopped tomatoes to it.
Once tomatoes soften, add turmeric powder and curry powder / red chilli powder.
Add chopped fenugreek leaves and mix well.
Add mashed lentils once the fenugreek leaves wilt and stir with a wooden spatula.
Let it come to a boil and simmer for few minutes on a low flame.
Heat oil or ghee in a pan and temper garlic cloves, curry leaves and 1/4th cup chopped onions.
Add the tempering to the dhal and give it a stir. Garnish with cilantro.
Serve hot with rice or roti.