Preheat oven to 300 degrees. In a large pot, melt the butter. Add beef broth and water and bring to a boil. Add the rice and stir.
Pour into a large casserole dish. Bake for 1 hour.
Remove casserole dish from the oven and stir the rice.
Add mushrooms, celery, green onions, and almonds. Stir until toppings are evenly distributed throughout the rice.
Bake for 20 minutes and serve immediately.
