Rinse the red beans. Add to a bowl, and cover the beans with about 1 inch of water.
Let sit for at least 6 hours or overnight. Drain the beans and set aside.
Press SAUTE on the Instant Pot. When hot, add the oil to the inner pot and swirl to coat.
Stir in the sliced sausage, and cook, stirring regularly, until browned, about 5-6 minutes.
Remove to a plate.
Stir in the onion, bell peppers, celery, garlic, salt, and Cajun seasoning.
Cook, stirring the entire time, until vegetables are soft, about 4-5 minutes.
Stir in the bay leaves, beans, water, and liquid smoke.
Close and lock the lid.
Turn the pressure release valve to SEALING.
Press MANUAL high pressure and adjust the time to 18 minutes.
Once the cooking time ends, let the pressure release naturally for 20 min.
Carefully turn the pressure release valve to VENTING to release any remaining pressure.
Remove the bay leaves.
Remove ⅔ of the beans, and set them aside.
Mash the remaining ⅓ of the beans.
Return the ⅔ of the beans to the pot, and stir in.
Stir in the sausage.
Press SAUTE, and simmer, stirring regularly, until slightly thickened.
Season with additional salt if necessary.
Serve with white rice topped with sliced green onions and a bit of Tabasco sauce, if desired.
Notes
Andouille sausage: You can substitute an equal amount of kielbasa.
Cajun seasoning: If you don't have/can't find Cajun seasoning, Creole seasoning makes a good substitute. Also, feel free to adjust the mount of seasoning to your liking.
Liquid smoke: I like the hint of smokiness liquid smoke adds. It reminds me of the slight smoky flavor you get when using a smoked ham hock. If you prefer, you can omit it.
Tabasco: I like using Chipotle Tabasco sauce with this recipe because the smokiness really compliments this dish. Feel free to use any type of hot sauce that you like or omit if you prefer.