1 tbsp Cajun seasoning (see blog post for homemade)
Add all ingredients to the slow cooker. Stir to mix well.
Cook HIGH 3-4 or LOW 6-8 hours.
Remove chicken from slow cooker. Shred with 2 forks and place shredded chicken back in the slow cooker.
Turn on the IP and select Sauté. Once hot add oil and sausage and cook a few minutes until sausage is browned. Remove sausage from the IP.
Add chicken and sear on each side. Remove chicken from the IP.
Add bell pepper, onion, and celery to the IP and cook 3-5 minutes or until soft. Pour broth into the Instant Pot, scraping off any browned bits from the bottom. Add garlic, diced tomatoes, tomato sauce, and Cajun seasoning . Stir to mix well.
Close lid and seal valve. Set high pressure and cook for 5 minutes (7 minutes if using chicken thighs). Quick release pressure.
Remove chicken from the IP. Shred with 2 forks and place shredded chicken back in the slow cooker.