Pat the chicken breasts dry. Rub each breast evenly with the 1 tablespoon Cajun seasoning.
Heat 2 tablespoons olive oil in a large skillet over medium-high heat until shimmering.
Add the seasoned chicken to the skillet and cook 3–4 minutes per side, until browned and cooked through. Remove the chicken to a plate and tent with foil.
Reduce the heat to medium and add the 2 cups long grain rice to the skillet; stir briefly to coat with any remaining oil.
Stir in 3 cups chicken broth, the drained 15-ounce can of black beans, the 15-ounce can of diced tomatoes with juice, 1 teaspoon chili powder, 1/4 teaspoon paprika, and 1/4 teaspoon cumin. Bring to a simmer.
Once simmering, reduce heat to low, cover the skillet, and cook 20–25 minutes until the rice has absorbed the liquid and is tender.
Return the cooked chicken to the skillet, nestling it into the rice, cover, and heat briefly until the chicken reaches 165°F (74°C).
Garnish with fresh chopped parsley and serve with sliced avocado.
