Melt ½ stick of the butter over medium heat in a large cast iron skillet. Stir in the onion and celery. Continue cooking until the onions are tender, about 5 minutes, stirring occasionally. Season to taste with Mesquite Smoke Seasoning or salt and pepper. Stir in the green chilies just until warmed.
Meanwhile, whisk together the cream of chicken soup and the water in a saucepan. Add the remaining ½ stick of butter. Bring to a boil over medium-high heat, stirring occasionally, until the butter melts.
Remove any excess fat from chicken breasts. Season the chicken well with Mesquite Smoke Seasoning or salt and pepper to taste.
In a 9x13-inch casserole dish, or 12 inch Dutch oven, evenly pour the rice along the bottom of the pan. Place the chicken on top. Note: you can cut the chicken breasts in half for smaller pieces. Evenly spoon the onion mixture on top of the chicken. Evenly pour the soup on top.
Cover with a lid or tinfoil. Bake at 350 degrees for about 1 ½ hours, or until the internal temperature of the chicken is 165 degrees F. Serve warm.