Mix broth and rice in a medium saucepan, and bring to boil. Reduce heat to low, cover, and simmer 20 minutes, until rice is tender and broth is absorbed.

In medium skillet, melt butter over medium high heat. Add onions and brown sugar. Sauté until butter is absorbed and onions are translucent and soft. Reduce heat, and cook onions for another 20 minutes, until they are caramelized.

Stir cranberries and mushrooms into the skillet. Cover and cook 10 minutes or until berries start to swell. Stir in orange zest, then fold the mixture into the cooked rice. Salt and pepper to taste.