Preheat your oven to 350°F (175°C). This will ensure your casserole bakes evenly and thoroughly.
In a large skillet, melt the butter over medium heat. Add the minced onion, green bell pepper, red bell pepper, and garlic. Sauté until the vegetables are tender, about 5-7 minutes.
Stir in the andouille sausage and cook for another 5 minutes until the sausage is browned and heated through.
Add the shrimp to the skillet, along with the salt, pepper, and Cajun seasoning. Cook until the shrimp turns pink and opaque, about 3-4 minutes.
In a large mixing bowl, combine the cooked rice, the sautéed mixture from the skillet, and the fire-roasted tomatoes. Mix well to ensure everything is evenly coated.
Transfer the mixture into a greased casserole dish. Top with the parmesan cheese and sprinkle the bread crumbs evenly over the top.
Place the casserole in the preheated oven and bake for 25-30 minutes, or until the top is golden brown and bubbly.
Once out of the oven, let the casserole sit for about 5 minutes before serving. Enjoy this Louisiana Casserole hot!
