Wash your hands and clean your preparation area. Rinse any fresh vegetables under cool running water before using.
Cook chicken in a skillet over medium-high heat. Cutting the chicken up into bite-size pieces until cooked through, about 10 minutes. Transfer to a medium bowl.
Heat the skillet to medium-high heat and add oil. Add onion and cook, stirring often, until translucent, about 2 minutes.
Add garlic, celery, and Cajun seasoning and cook, stirring often, for about 30 seconds.
Add flour and cook, stirring to coat the vegetables, until the flour browns, about 1 minute.
Add tomatoes and cook, stirring occasionally, until they begin to release their juices, about 2 minutes.
Stir in broth, cover, increase heat to high and bring to boil.
Return the chicken to the skillet, along with okra and brown rice; reduce the heat to a simmer.
Cook until the okra is heated through, about 10 minutes.