Brown and crumble sausage in a large skillet.
When sausage is about half cooked, add onion, celery and red pepper flakes then continue cooking until sausage is no longer pink and veggies are starting to become translucent.
Spray a medium-sized casserole dish (1.5 quarts) with cooking spray or rub with butter.
In a separate bowl, whisk together broth and soup until smooth. Pour soup mixture and rice into skillet and stir until all ingredients are thoroughly incorporated.
Pour into prepared casserole dish, cover tightly with aluminum foil then bake at 350 degrees for 1 hour or until rice is tender.
Remove casserole from oven and let rest, covered, for 15 minutes before serving.
Recipe adapted from South Your Mouth