In a large saucepan, bring 2½ cups water and rice mix to a boil over medium-high heat. Reduce heat; cover and simmer for 25 minutes.
Spoon rice into a large bowl. Add chicken, tomatoes, 1 cup cheese, celery, and cream, stirring to combine.
Preheat oven to 350°.
Add vegetable blend to saucepan; cook over medium heat until water has evaporated, about 5 minutes. Stir into rice mixture to combine. Spread mixture in a 2-quart baking dish. Top with remaining 1 cup cheese.
Bake until hot and bubbly, about 20 minutes. Garnish with green onion, if desired.
Recipe by Paula Deen Magazine at https://pauladeenmagazine.com/chicken-and-jambalaya-rice-casserole/