Pick, rinse and soak 1 cup dry rajma or red kidney beans in 4 cup water for 8-12 hours. Rinse the soaked beans thoroughly multiple times in cold water. By now the beans should have doubled in size.
Place the inner pot in your instant pot and switch it on. Press saute button and once it displays hot, add 2 tablespoons oil. Add cumin seeds and fry for few seconds.
Next add 1 cup finely chopped onions and saute for a minute.
Now add minced ginger garlic, slit green chili and sate well. You can add ginger and garlic paste if fresh ones are not available.
Now pour the tomato puree and mix.
Add garam masala, coriander powder, turmeric powder and red chili powder. Mix well and saute for 3-4 minutes well.
Now let the tomatoes cook thoroughly. This takes between 12-15 minutes. Once they are well cooked oil will ooze from the sides.
Once the tomatoes are well cooked, add 1/2 cup water to de glaze. Mix well.
Now add drained kidney beans and mix well. Add 2.5 cups water and salt to taste
Close the instant pot. Cancel saute mode.
Set the pressure valve to seal and press the pressure cooker mode. Set time to 35 minutes.
Once done, release pressure manually. Simmer for 15-20 minutes in saute mode. You can add 1/2 cup to 1 cup water if the curry is very thick.
Add chopped coriander leaves and kasuri methi. Mix well. Serve rajma with rice for rajma chawal or roti.