Add the sliced smoked sausage to a large saucepan over medium heat. Cook until browned.
Add the frozen peppers and onions (and celery, if using). Sauté until the onions are soft and translucent.
Stir in the chopped rotisserie chicken and cook for a few minutes, just until the chicken browns slightly and everything is well combined.
Add the jambalaya rice mix and substitute chicken broth for the water listed on the box.
Bring the mixture to a boil, then cover, reduce the heat, and simmer for the amount of time directed on the box.
Fluff, taste, and adjust seasoning if needed. That's it!!!