1/3 cup dried cranberries 3 tablespoons unsalted butter ( cut into 3 pieces, divided ) 2 tablespoons vinegar, balsamic 3 cups water 3 cups milk 1 1/2 cups polenta ( medium ground polenta - not instant ) 1 cup fontina cheese, shredded 1/4 cup asiago cheese ( grated ) 1/4 cup parmesan cheese, grated 1/4 cu