In a large saucepan melt butter over medium heat. Add onion and cook until soft, 5 minutes. Add rice and stir until translucent, 2 to 3 minutes. Add cranberries and stock and stirwell. Bring to a boil, reduce heat, and simmer until tender, about 18 minutes. Season to taste with salt and pepper. Stir in parsley just before serving. Yield 6 to 8 servings
