Wash the lentils 2 to 3 times with water. Drain the water and keep the lentil aside. Heat oil in an instant pot on sauté mode.
Once the oil is hot, add onion, celery, carrots, and potatoes. Saute for a few seconds.
Now add washed lentils, vegetable stock, salt, cumin powder, paprika, and crushed black pepper. Mix everything well.
Cover the instant pot with its locking lid, turn off the sautéing mode, press the manual/pressure cook button, and set the timer for 12 minutes under high pressure.
Once cooking time is done, let the pressure release naturally for 10 minutes and then quickly release the remaining pressure.