Turn on the Instant Pot and set to Saute mode. Once it's heated, add in oil and cumin seeds.
Once the cumin seeds start to sizzle, add in the garlic, ginger and chopped onions. Fry for a few minutes, stirring occasionally, till onions start to brown.
Add in spices and salt, and give it a quick mix. Add in chopped tomatoes and let it cook for a couple of minutes till the tomatoes start to soften and pulp.
Mix in the lentils and water and let it come to a quick boil. Put on the lid and set the Instant Pot to manual Pressure Cook mode for 8 minutes, making sure that the valve in on the sealing position.
Let the pressure release naturally before removing the lid. Give it a good stir and garnish with cilantro leaves before serving.