Clean, wash and soak both the rajma and urad dal for 3-4 hours or overnite. If you do not have much time of soaking the dal then you can put both the rajma and urad dal in hot water and leave it for an hour.
After soaking drain all the water and transfer it in a pressure cooker to boil.
Add salt, 4 cups of water (add water upto immersing level). Mix it well.
Close the lid of pressure cooker and cook dal over medium flame for 8-9 whistles. Turn off flame.
Allow the steam to escape naturally before opening the lid. If they are not cooked thoroughly, then add water accordingly and pressure cook for few more whistles.
Mash the dal with laddle or the large spoon after cooking the dal in pressure cooker.
Let’s prepare our seasoning.
Heat butter/ ghee in a pan, once the butter melts adds chopped onion and saute on medium flame till the onion becomes translucent or light brown.
Add ginger garlic paste and saute for a minute till the raw smell goes away.
Add ¾ tsp of red chilly powder and mix it well.
Add tomato paste (Grind tomatoes to make paste) and sauté till it starts leaving the sides of pan and all the moisture gets evaporated and it becomes just like thick paste.
Add cumin powder and few chopped coriander leaves and saute it for a minute.
Add cooked dal and rajma with its water, mix it well.
Dal Makhani is usually has medium to thick consistency so add more water as per requirement and bring it to the desired consistency.
Add garam masala, remaining red chilly powder and mix it well.
Add salt to taste (I have added salt while boiling the dal and rajma so add salt accordingly)
Cook dal on low flame for 6-7 minutes till you get the smooth and creamy texture. Keep on stirring in between so that it does not stick to the bottom of a pan. You can add more water if required.
Lastly add fresh cream, freshly chopped coriander leaves and stir for a minute.
Garnish with some chopped coriander leaves, fresh cream and serve.