In a medium sized pot, bring chicken stock to a boil on high heat. Once boiling add rice, reduce to medium-low heat, and cover. Cook for 30 minutes, or until soft and most of the liquid has been absorbed.
While the rice is cooking, cut off the bottom portion of the celery, rinse stalks and remove leaves. Pat dry and thinly slice. Set aside in a bowl.
Dice your onion and mushrooms and add to the bowl of celery.
Preheat your oven (if needed) to 350 degrees.
In a large pan and heat on medium. Once hot, add pine nuts and toast lightly, stirring frequently so they don't burn. Once golden, remove from heat and set aside.
Using the same pan, add ground sausage, break apart into small pieces, and cook thoroughly.
Add vegetables and stir regularly for even cooking. Cook for 7-8 minutes.
Add vegetables and stir regularly for even cooking. Cook for 7-8 minutes. Stir in pine nuts, cranberries, rice, salt, and pepper. Mix well.
Pour into a 13 x 9 glass pan and bake for 20 minutes. Serve warm.