I used to make this on the stove top all the time, but now I prefer to use
the Instant Pot. Whip up a batch whenever you have a few minutes to spare, and it will stay piping hot until you’re ready to enjoy it. The soup is brightly flavored from the squeeze of lemon juice stirred in at the end of cooking. That addition really makes the dish, so don’t skip it! Serve the soup drizzled with extra-virgin olive oil and sprinkled with sumac (a lemony Middle Eastern spice) for a fresh, peppery finishing touch.
Select the Sauté setting on the Instant Pot and heat the olive oil. Add the carrots, celery, onion, and salt and sauté for about 5 minutes, until the onion has softened and is translucent.
Add the lentils, water, and bay leaf and stir well.
Secure the lid and set the Pressure Release to Sealing. Press the Cancel button to reset the cooking program, then select the Select the Soup/Broth setting and set the cooking time for 15 minutes at high pressure.
Let the pressure release naturally for at least 10 minutes, then move the Steam Release to Venting to release any remaining steam.
Open the pot and stir in the lemon juice, then taste and adjust the seasoning with salt if needed.
Ladle the soup into bowls, top each serving with a drizzle of extra-virgin olive oil and a sprinkling of sumac, and serve right away.
If you like, add 1 teaspoon of a favorite spice blend to the soup when you add the lentils. Garam masala, ras el hanout, and berbere are three of my favorites.