Dice the onion. Dice the fennel. Peel and dice the carrots. Grate the garlic and set aside to stir in once the soup is cooked.
Turn on Saute mode and add the olive oil. When it is heated, add the onion and fennel and saute for 6 to 7 minutes until translucent. Add the carrots, lentils, tomatoes, broth, water, salt, paprika, and oregano. Lock the lid of the Instant Pot. Place the pressure release handle (vent) in the “Sealing” position.
Cook on High Pressure for 10 minutes: Press the Pressure Cook button, making sure the “High Pressure” setting is selected, and set the time. Note that it takes about 20 minutes for the pot to “preheat” and come up to pressure before it starts cooking. (During cooking, avoid touching the metal part of the lid.)
Quick release: Vent the remaining steam from the Instant Pot by moving the pressure release handle to “Venting”, covering your hand with a towel or hot pad. Never put your hands or face near the vent when releasing steam. Open the pressure cooker lid.
Stir in the spinach and grated garlic, and allow it to rest for 5 minutes before serving. Taste and season with additional salt and fresh ground pepper as necessary. Serve immediately.