Pour the beans into the Instant Pot. Add enough water to cover the beans by 1-inch, roughly 4.5-5 cups of water.
Add two teaspoons of salt. Replace the lid and seal. Set the Instant Pot to manual, then set the time to 0 minutes.
Let the pressure from the beans release naturally. This should take about 15 minutes. You do not need to drain the beans.
Add the sliced Andouille or smoked sausage, minced garlic, diced celery, diced onion, diced green bell pepper, Cajun seasoning hot sauce (optional), dried thyme, bay leaves, and chicken stock. Stir everything until combined.
To cook the rice, place a 3-inch trivet into the pot, over the red beans mixture. Set an oven safe bowl on top of the trivet.
Add rice to the oven-safe bowl. Add ¾ cup of water or chicken stock per one cup of rice. Season the rice with salt to taste.
Replace the lid and seal the pot. Set the pot to manual pressure, then set the timer for 30 minutes. Afterwards, let the pressure release naturally, about 15-20 minutes. Once the pressure has released and you’ve removed the lid, carefully lift the oven safe bowl and the trivet out of the pot and set aside. Remove the bowl of rice from the trivet and fluff the rice with a fork.
Remove and discard the bay leaves. Serve the red beans over the hot cooked rice. Garnish with chopped green onions or diced parsley if desired. Sprinkle with more hot sauce for additional heat.