Prepare the Lentils: Rinse the lentils and look them over for any debris or malformed lentils.
Sauté: Put the onion, carrot, celery, and garlic in a food processor; pulse until the vegetables are finely chopped. Choose the sauté button on the Instant Pot. When the oil is hot, sauté the chopped vegetables for about 2 minutes, stirring frequently.
Add Remaining Ingredients: Add the vegetable broth to the pot and scrape any browned bits, if necessary. Add the rinsed lentils, thyme, bay leaves, salt, and pepper.
Pressure Cook: Make sure the steam release knob is in the sealing position. Select the pressure cook function, high pressure, and set the timer for 6 minutes. When the time is up, let the pressure come down naturally for 5 minutes and then carefully release the remaining pressure. Drain off any excess liquids.
Serve: Spoon lentils into serving bowls or plates and enjoy with crusty bread or rolls.