Rinse the rice until the water runs clear. This helps remove starches that may otherwise scorch at the bottom of your Instant Pot.
Optional step: Soften first the onion and then garlic with the oil using the sauté function. Deglaze with a couple tablespoons of water and scrape up any brown bits. There should be NOTHING left stuck to the bottom, otherwise the Instant Pot will not be able to pressurize properly.
Then add bell peppers, tomato paste and 1 teaspoon Cajun seasoning (or more to taste and more heat). Stir until well combined.
Pour the broth over the veggie mixture and arrange the chicken breast halves over top. Now spread the rinsed rice on top and DO NOT stir!
Close the lid and turn the valve to ‘Sealing’. Cook on ‘Manual’ high pressure for 7-8 minutes (the latter at high altitude).
Let the pressure release naturally (NPR) for 5 minutes, then release remaining pressure by turning the valve to ‘Venting’.
Serve with chopped cilantro and a squeeze of lime juice.