Add the lentils and water or broth to the inner pot of the Instant Pot. Add salt, pepper, and any other seasonings of choice. Stir to combine.
Secure the lid and select the Pressure Cook setting. Set the timer to 6 to 8 minutes for al dente lentils, or 10 minutes for softer lentils.
When the timer beeps, allow a natural pressure release for 10 minutes. Perform a manual pressure release to vent any remaining steam. Open the pot, discard any aromatics, and transfer the lentils to a bowl or tupperware using a slotted spoon.
Store cooked lentils in an airtight container in the fridge for 5-7 days, or freeze for 4-6 months.