Discard any stones, grit, debris from the lentils, rinse the lentils under running water, soak the lentils with about 2 cups of water for 10-15 minutes. Meanwhile start prepping up with chopping the onions, tomatoes etc.
Press the saute button (normal heat setting), once it displays 'hot' add the oil. Once the oil is hot, add the cumin seeds, let them crackle.
Next, add the chopped onions, sauté until it turns golden brown.
Add ginger garlic paste, sauté until fragrant.
Add the chopped tomatoes, cook stirring occasionally, until the tomatoes have turned mushy, cooked well, and have reduced down creating a thick mixture.
Add all the dry spices along with salt, mix well and cook for another 30 seconds.
Add the drained lentils (discard the water it was soaked in), mix it well with the onion-tomato-spice mixture.
Add the water or stock, mix well.
Press cancel, close the lid of the Instant Pot with the valve on sealing position. Press the manual or pressure cook button and pressure cook on high for 12 minutes. It will take some time for the pressure to build up, about 10 minutes after which the timer will start.
Let it depressurize naturally (takes about 15 minutes). Once the float valve (silver pin) drops, open the lid, and give it a quick mix.
Select cancel, and press the saute button again. Add the coconut milk and mix well, let the curry simmer for two more minutes. Check for seasoning and adjust with more salt if required.
Finish it off with a squeeze of lemon juice, 1/4 teaspoon more of garam masala (optional) and freshly chopped cilantro/parsley. Serve this instant pot lentil curry with rice or any flatbread of your choice.