Add the oil to the bottom of your Instant Pot and turn on in the Saute mode.
Add the sausage slices and saute, then remove and place to the side.
Add the diced onion, bell pepper and celery and cook until translucent.
Add the garlic and cook 2 more minutes. Add 3 Tablespoons of the butter and melt into the vegetables.
Add back the sausage, red beans, seasonings, 2 cups of the water and stock and stir well to combine.
Turn the Instant Pot into High Pressure mode, move lever on top to Sealing and cook for 50 minutes.
Allow a natural release for 15 minutes at which point carefully move lever to venting to release any pressure that’s left.
While the Instant Pot is in release mode cook the rice. Add two cups of rice to a medium pot, add two cups of water and 1 Tablespoon Butter. Cover with a lid and bring to a boil.
Turn down the heat all the way to low and simmer for 15 minutes. Do not lift the lid at all during the cooking of the rice.
Stir the red beans and smash a few on the sides, this will thicken them.
Serve the red beans with the rice and top with chopped green onions.