Arrange an oven shelf at the bottom third of the oven. Preheat oven to 350°F (177ºC). Generously butter a 9×13 casserole baking dish or spray with nonstick cooking spray.
In a 12-inch skillet, brown and crumble the sausage (1 pound). Transfer the cooked sausage to a paper towel-lined plate. Drain and discard all but 2 tablespoons of sausage drippings. If there aren't 2 tablespoons drippings in the skillet add butter to make up the difference.
Add celery (1 cup), onion (1 cup), garlic (3 cloves), and red pepper (1/2 cup) to skillet with pan drippings and sauté, on medium-low until onion is translucent, about 7 minutes.
While the veggies are sautéing, pour about 1/4 cup chicken broth, from the can, into a glass 1 cup liquid measuring and microwave for 20-30 seconds, or until the Better Than Bouillon (1 tablespoon) softens enough in the warm broth to whisk into it. If you have a few bits that don't easily dissolve, mash them against the side of the measuring cup with the back of a spoon.
Add the dissolved Better Than Bouillon with the remaining chicken broth and the cream of mushroom soup (1 can). Whisk until most of the cream of mushroom soup incorporates into the liquid. It's okay to have some lumps, they will melt in when the casserole cooks in the oven.
Add the rice (1 cup) and cooked sausage to the skillet.
Pour the mixture into the prepared pan. Cover tightly with foil.
Bake for 65-70 minutes, stirring casserole halfway through cook time. Check the rice. If the rice is tender and cooked through, remove the pan from the oven and let it stand for 10 minutes. If the casserole has cooked for 1 hour and the casserole liquid is gone, yet the rice isn't tender, add more chicken broth or water, cover, and cook until tender.
Fluff rice with a fork. Serve and enjoy!