Cut the chicken into bite-size pieces. Drizzle with a little olive oil and season generously with Cajun seasoning, or use another seasoning blend you like.
Set a large deep skillet or braiser over the heat and let the pan get hot. Add the chicken and leave it alone for a couple of minutes so it can get some color. Toss or turn the pieces and brown the other side. Cook until the chicken is about three-quarters of the way done.
Add the pasta shells from the macaroni and cheese box to the skillet. Toss them with the chicken so they pick up the seasoning and flavor from the pan.
Pour in just enough water to cover the pasta. Cook uncovered, stirring as needed, until the shells are tender and most of the water has cooked away. If a small amount of liquid is still left once the pasta is done, carefully drain it off.
While the pasta cooks, microwave the frozen broccoli according to the package directions. Add the cooked broccoli to the skillet and stir it through. Skip the broccoli if you do not want it.
Add the cheese sauce packet from the macaroni and cheese box and stir until the pasta, chicken, and broccoli are coated.
Pour in about 1/2 cup buffalo wing sauce, adding a little more if you want extra tang or heat. Add the ranch seasoning packet and stir everything together until thick, creamy, and heated through.
Make sure the chicken reaches a safe internal temperature of 165°F before serving.
Spoon into bowls and finish with chopped green onions. Add blue cheese crumbles if that is your thing.