Season the chicken breasts with Cajun seasoning and sear them until browned on both sides. Remove the chicken from the skillet.
In the same skillet, add diced onion, bell peppers, celery, and minced garlic. Sauté until they become tender and fragrant.
Mix in the condensed cream of chicken soup and chicken broth. Stir until the sauce is smooth and heated through.
Place the seared chicken breasts back into the skillet, nestling them into the sauce.
Sprinkle shredded cheddar cheese over the chicken and sauce mixture.
Open the can of refrigerated biscuits and arrange them evenly on top of the casserole.
Bake in a preheated oven at 375°F (190°C) for 25-30 minutes or until the biscuits are golden brown and the chicken is cooked through.