Heat Instant Pot on Sauté mode. Add 1 tablespoon oil to pot and once it is heated, add the 12 ounces andouille sausage and 1 pound raw shrimp. Arrange in a flat layer and let it sear, undisturbed, until the bottom begins to brown. Stir the meat, and continue cooking until the shrimp are done as indicated by them being white, firm, and no longer translucent. Do not over cook the shrimp. Transfer both the sausage and shrimp to a separate bowl.Note - to get the best sear, you may want to do this step in batches to avoid over crowding. It will take longer but the result will be better.
Still using sauté mode, add the 1/2 pound boneless skinless chicken breasts and 1/2 pound boneless skinless chicken thighs. Arrange in a flat layer and let them sear, undisturbed, until the bottom begins to brown. This should take about 4-5 minutes. Remove the chicken and set it aside in a separate bowl.
Still using sauté mode, add 1 1/2 cups uncooked long grain white rice and allow it to toast for a couple of minutes.
Add the 2 medium yellow onions, 1 green bell pepper, 3 stalks celery, and 2 cloves garlic to the pan with the rice. Stir to coat and sauté for about 5 minutes until the vegetables are tender.
Add the cooked chicken along with any juices in the bowl, the 14 1/2 ounces canned diced tomatoes, the 14 1/2 ounces chicken broth, a dash of cayenne pepper, 1 heaping teaspoon chili powder, 1 level teaspoon cumin, 1/2 teaspoon dried thyme, 1/2 teaspoon kosher salt, and pinch of smoked paprika to the Instant Pot. Stir everything well to distribute the liquid.
Secure the lid and cook on high pressure for 10 minutes.
When done, quick release the pressure. Open the lid, add the shrimp and sausage, and stir to combine. Add cayenne pepper sauce, if desired, as this recipe is very mild without it.
To serve, scoop into a bowl and garnish with 2 tablespoons chopped fresh flat-leaf parsley and chopped scallion.
Notes
Burn notice - If you have an Instant Pot that tends to give you a burn notice, it may happen during the pressure cooking portion of this recipe. If it does, release the pressure, open the lid, stir everything well, and continue cooking.