Drain juice from mandarin oranges into a 1 quart measuring cup.
Add enough water to cup to make 2 1/2 cups liquid. Add to a 2 quart non-stick saucepan, and heat to boil. Add rice, cloves, and whole cinnamon. Return to a boil, cover, and simmer for about 20 minutes (until liquid is absorbed). Remove from heat and allow to sit 5 minutes.
Meanwhile, in a small non-stick skillet, melt the butter, and saute the onions until clear. Add the mushrooms, and cook until moisture evaporates. Do not brown.
Remove the whole cloves and whole cinnamon stick from the rice.
Lightly grease a ring mold. Arrange 1/4 cup of the mandarin oranges to the bottom of the mold.
In a large bowl, combine the remaining mandarin oranges, almonds, and onion/mushroom mix to the rice. Mix well.
Spoon rice into mold and refrigerate for 2-4 hours, or overnight
When ready to eat, remove from rice ring mold onto a cookie sheet. Bake for 20 minutes in a 250° oven or until heated through. Remove from oven and serve.