Turn Instant Pot on “saute” on high. Once hot, add in olive oil and sausage and stir until evenly browned on all sides.
Once sausage is evenly browned, add in onion, green pepper, celery and garlic and saute until onions are tender. Stir well and use the liquid from the vegetables to deglaze the bottom of the pot. Do so by gently scraping the bottom of the pot with your spatula to get all of the browned sausage bits off the bottom of the pot.
Once all vegetables are tender, add in Cajun seasoning, thyme, salt and pepper.
Stir well and then pour in beans and chicken broth. No need to stir. Add in the bay leaves.
Close pressure cooking lid and set timer to 60 minutes. Make sure that the pressure cooking valve is in the “sealed” position. When the timer beeps, naturally release the pressure for 15 minutes and then remove lid.
Remove the bay leaves, which should be right on top.
Using a potato masher, mash the red beans 5 or 6 times. You do not want to mash all of the beans, just enough to break open some of the beans to increase the creaminess of the red beans.