Soak black whole gram and kidneybeans for 3 hours atleast.
Start the instant pot in sauté mode and heat oil in it. Add cumin and black cardamom. When cumin starts to crackle, add onion and minced garlic. sauté for 2 minutes.
Add salt, red chili powder, turmeric powder, coriander powder and mix well.
Add soaked rajma(kidney beans), urad(whole black gram) and water.
Change the instant pot setting to manual or pressure cook mode for 60 minutes(1 hour) at high pressure with a vent in sealing position.
When the instant pot beeps, let the pressure release naturally.
Now, open the lid and gently mix and mash the curry with the back of your spatula.
Also, add fresh cream and mix well.
Add some butter if you like. Garnish with cilantro and serve hot.
Video
Notes
Always soak black gram and kidney beans for 3 hours at least.
You can add butter along with cilantro however it is totally optional.
Use either store-bought and homemade cream.
If you want to make this recipe dairy-free then completely avoid butter and replace fresh cream with cashew cream or cashew milk.