Wash and rinse urad dal (whole black lentil) and rajma (kidney beans) in a large bowl. Soak in 3 cups water overnight.

In the morning, drain the water in which the dal and rajma was soaked. Transfer the dal and rajma to a pressure cooker with 1 teaspoon salt. Add around 3.5 cups water.

Pressure cook on high-medium heat for 2 whistles, then lower the heat to low-medium and cook for another 20 minutes.

Mash some of the dal and rajma using a potato masher. Then turn on the heat to lowest heat and let the dal simmer while you make the masala.

To make the masala, in a large pot/pan, heat 2 tablespoons butter  (I use and recommend amul salted butter here) and 1 tablespoon ghee on medium heat.

Once the butter melts and is hot, add the finely grated onion. Cook the onion for around 6 to 7 minutes or until it turns light golden brown. Keep stirring it continuously so that it doesn't burn and keep heat on medium.

Add the ginger garlic paste and cook for 1 to 2 minute until the raw smell goes away.

Add in the boiled dal and Add 1/2 cup water, stir and set heat to low. Let it simmer on low heat uncovered for around 45 minutes. 

Stir often (every 10 minutes or so) else dal will stick to the bottom of the pot. You will also need to add water. I added total of 1.5 cups water as the dal was simmering.

Garnish dal makhani with more cream and coriander serve with butter. Enjoy!