How to Make It
Turn your Instant Pot to the sauté function. Add one tablespoon of the neutral oil and the sliced sausage to the bottom of the pot. Sauté until the sausage is browned on both sides, about seven minutes.
Add the other two tablespoons of oil along with the onion, bell pepper, celery, and garlic. Cook until the onions are soft and just getting brown around the edges. Add in the chicken stock and use a wooden spoon to scrape up any brown bits stuck to the bottom of the pot.
Add the red beans, Cajun seasoning, a few grinds of black pepper, and the bay leaves. Add five cups of water to the mixture. Turn sauté mode off. Seal the lid and set the Instant Pot to high pressure for 40 minutes.
While the red beans cook, cook the rice.
When the beans are done, allow the pressure to naturally release. Season the beans with salt, pepper, more Cajun seasoning, and hot sauce, to taste. Using a wooden spoon or potato masher, smash the beans to your desired consistency. They may look soupy, but they will thicken as they sit. Serve over hot rice with a sprinkling of green onions and more hot sauce as desired.