Season the chicken breasts with Cajun seasoning, ensuring each piece is well coated. Heat olive oil in a large skillet over medium-high heat. Sear chicken for about 5-7 minutes on each side, until golden brown. Remove chicken and set aside.
Add more olive oil if needed. Add chili powder, paprika, and cumin to the skillet, stirring for about 30 seconds until fragrant.
Add the long grain rice to the skillet, stirring to coat with spices. Pour in chicken broth, add drained black beans and diced tomatoes. Stir to combine.
Bring to a gentle simmer, then reduce heat to low. Place seared chicken breasts on top of rice mixture. Cover and cook for about 20 minutes until rice is tender.
Remove from heat, let rest a few minutes. Fluff rice with a fork, mixing in chicken and beans. Garnish with parsley and serve with avocado.
