Preheat the Instant Pot using the SAUTE function.
When the display panel says HOT, add the onion and bell pepper. Cook, stirring frequently, until the vegetables brown and begin to stick to the bottom of the pot, about 6 minutes.
Stir in 3 tablespoons of broth and continue to cook, stirring, until onion is soft and lightly browned. Stir in garlic and chili powder. Cook 1 min, stirring continually.
Add tomatoes, lentils, and remaining broth. Place the lid on the cooker and make sure the pressure knob is in the SEALING position. Using the display panel select the CANCEL button. Then the MANUAL/PRESSURE COOK function, high pressure, and use the +/- buttons until the display reads 15 minutes.
When the cooker beeps to let you know it’s finished, wait until the display reads LO:10 before switching the pressure knob from the sealing to the venting position. Remove the lid and stir the chili, add the cilantro and salt to taste.
If you have a ripe avocado on hand, it makes a wonderful topper, and adds just the right amount of creaminess.