Set the Instant Pot to Saute mode and heat oil. Once hot, add the chopped onions, garlic, and ginger. Sauté until the onions are translucent and fragrant, about 3-4 minutes.
Add the tomatoes, curry powder, ground coriander, cayenne, and salt. Mix well and sauté for 5-7 minutes.
Drain and rinse the soaked chickpeas and add them to the Instant Pot along with the green lentils. Add 4 cups of water and mix well.
Close the lid, set the valve to the sealing position, and select "Pressure Cook" or "Manual" on high pressure. Set the timer to 15 minutes. Allow a natural pressure release for about 10 minutes, then manually release any remaining pressure.
Open the lid and put the Instant Pot in saute mode. Add the yogurt and garam masala and simmer for 2-3 minutes. Cancel saute mode and garnish with cilantro. Serve warm.
Notes
Soak the dried chickpeas overnight. This helps them cook more evenly and reduces cooking time. If you're short on time, use the quick soak method.
Whisk the plain yogurt before adding it to the curry to ensure a smooth and creamy texture.
Add the yogurt after pressure cooking to prevent it from curdling.