Using the Sauté function, Sauté onions and carrot in the oil for about 5 minutes.
Stir in the garlic, garam masala, curry powder and chilli powder and sauté for a further minute, then press Off to stop the sauté function.
Stir in the lentils and water, and use a wooden spoon to deglaze the bottom of the pot to remove any burnt bits.
Pour the chopped tomatoes on top and add the tomato puree, but do not stir.
Secure the lid on the Instant Pot and Pressure Cook for 10 minutes at high pressure.
Note that it can take up to 10 minutes for the Instant Pot to pressurise before the cooking begins.
Quick Release the steam (careful!), then stir in the coconut milk, spinach and lemon juice until the spinach wilts.
Taste and season with salt and pepper and add more chilli powder if desired.