Preheat oven to 350 degrees F.
Season chicken on all sides with 1 ½ tablespoon of the Cajun spice mixture.
Heat 1 tablespoon oil in a large, straight-sided skillet (with a tight fitting lid) over medium-high heat. Add chicken (skin side down) and cook until browned all over, about 2 minutes per side. Transfer chicken to a plate.
(If using skinless chicken thighs or pan is dry, add remaining tablespoon of oil*). Add the onion and bell pepper. Season with generously with salt and pepper. Cook until softened, about 2-3 minutes. Reduce heat to medium and add the rice, stirring to coat. Add the stock, beans, diced tomatoes and remaining ½ tablespoon of the Cajun seasoning. Stir to combine and increase heat to medium high.
Add the chicken, skin side up, back to the skillet, nestling it on top of/partially in the rice. Bring contents to a simmer. Immediately cover the skillet with the lid and transfer to the preheated oven.
Bake for 25 minutes and remove lid. Continue to bake, uncovered, for 10-15 minutes or until most of the liquid is absorbed and the chicken is cooked through. Remove from oven and let sit for 5 minutes.
Garnish with parsley and jalapenos if desired. Enjoy!