Wash and chop all your vegetables
Press sauté mode on the instant pot and add oil.
Once the oil is hot, add the onion, carrot, and celery, sauté for 5 minutes.
Cancel sauté mode and add the lentil, diced tomatoes, broth, salt, and pepper, stir.
Close the lib of the instant pot, place the valve in the seal position, select manual high pressure, and add 12 minutes. The pressure will take about 15 - 20 minutes to rise and start cooking.
After 12 minutes, release the pressure immediately, and open the lid carefully.
Stir in parsley and serve.