Add the chicken thighs to the slow cooker. Drizzle a little olive oil over the top. Season with the Creole seasoning.
Add the diced tomatoes over the chicken, then the vegetables over top of the chicken. (Adding them while still frozen is fine!) Sprinkle a little more seasoning over top. Add a few dashes of salt and pepper as well.
Set the slow cooker on low and cook for 8 hours.
About 1 hour before dinner time, start cooking the brown rice. Cook according to package instructions. (If using instant brown rice, you'll only need a few minutes!)
Serve Slow Cooker Creole Chicken and veggies over brown rice.