On the saute setting, heat oil in the instant pot and cook the sausage until golden brown. Remove and set aside.
Add the chicken and shrimp to the instant pot and cook on saute setting for 5 minutes or until fully cooked. Add the sausage back to the pot and allow to cook together for one additional minute. Remove the mixture and set aside.
Continue using the sautee setting to cook the onion, bell pepper, celery and bottoms of the green onion. Cook for 2 minutes or until tender. Add garlic and cook for one additional minute.
Pour in 1/2 cup of chicken broth and use a wooden spoon or spatula to deglaze the pot, scraping any stuck on bits off of the bottom of the pot.
Stir in the white rice, tomatoes, remaining chicken broth and Cajun seasoning until well combined. Stir in the chicken, shrimp and sausage.
Place the lid on the instant pot in the sealing position and cook on manual high pressure for 5 minutes.
Allow the pressure to naturally release for 5 minutes before moving to the quick release.
Add salt and pepper to taste and top with sliced green onions if desired.
Notes
Storage - Leftover Jambalaya can be stored in an airtight container in the fridge for up to 3 days.Reheating - Jambalaya can be reheated in the microwave or in a skillet on the stove. If reheating on the stove, you can add a splash of water or broth to keep it from drying out.