Set the Instant Pot on the SAUTE setting, when the message HOT is displayed add 1 tablespoon of oil. Cook the sausage for 5 minutes or until it’s golden brown. Remove onto a plate and set aside.
Add 1 more tablespoon of oil, and the chicken then season with 1 teaspoon Cajun seasoning. Cook for 5 minutes or until it’s cooked through. Remove onto a plate and set aside.
Add the onion, celery, bell pepper, and garlic and cook for 2-3 minutes.
Add the remaining Cajun seasoning, dried basil, salt, pepper, diced tomatoes, sugar, rice, and chicken stock. Stir everything together, and make sure that there’s nothing stock to the bottom of the pot from the sautéing earlier (scrub with a wooden spoon).
Cover with the lid, make sure that the valve is in SEALING position. Choose the PRESSURE COOK/MANUAL setting on HIGH. And Pressure cook for 4 minutes, then naturally release the steam for 10 minutes. Quickly release the rest of the steam.
Carefully open the lid, and add the shrimp along with the cooked sausage and chicken. Cover with the lid and let the shrimp cook from the heat of the pot (residual heat) for 5-10 minutes (the shrimp is cooked when it turns pink and opaque/no longer translucent). Lightly stir, garnish with chopped green onion and parsley and serve.