Set Instant Pot to Saute on medium heat. Add olive oil, onion, celery, carrot and green pepper. Saute 2-3 minutes until onion is just softened
Sprinkle Cajun seasoning over vegetables and stir. Add in sausage & chicken and cook another 3-4 minutes until lightly browned. It doesn't need to be cooked as the pressure cooker will do that when the rice cooks.
Pour the diced tomatoes over top of the cooked meat and vegetables. Don't stir. Pour in the chicken stock, and then the rice. Do NOT stir. This layering stops the rice from settling to the bottom and causing it to set off the BURN warning.
Place the lid on the Instant Pot, close it and set the steam valve to seal. Cancel the Saute function and set the Instant Pot to Pressure Cook on High for 9 minutes. When time is up, cancel the pressure cooking setting and immediately open the steam valve to do a Quick Release of all the pressure.
Open the lid, stir the rice which will be on top to combine with the meat, vegetables and tomatoes. Now place the raw shrimp in the pot, stir and replace the lid. Let it sit 3-5 minutes until shrimp are cooked and a nice light pink colour.
Serve sprinkled with diced green onions or parsley if desired.
Instant Pot Cajun Jambalaya https://www.loveonaplate.net/instant-pot-cajun-jambalaya/