Set Instant Pot to sauté mode. Heat oil or vegan ghee and cook the onion-cashew paste for 30 seconds, stirring occasionally. Priya's tip - Add one-fourth cup of water to prevent the paste from sticking to the bottom.
Crush dried fenugreek leaves between your palms, add to the pot, and sauté for another 30 seconds.
Add tomato-green chili puree and salt. Stir and cook for 30 seconds to enhance the flavors.
Add green peas and one-fourth cup of water. Remember, mushrooms will release moisture as they cook, so do not add more water.
Mix in turmeric, coriander powder, red chili powder, and garam masala. Stir well to combine.
Rinse mushrooms thoroughly and add directly to the pot. Stir to coat with the masala. No extra water needed.
Cancel sauté mode. Secure the lid and set the valve to sealing. Pressure cook on manual mode for 4 minutes.
Perform a quick pressure release, carefully open the lid, and stir in vegan sour cream or cashew cream for richness.
Top with fresh cilantro, mix gently, and serve hot with roti, naan, or rice.