Heat a pan over medium heat, and pour in the port wine. When the wine is heated, pour in the beer. Sprinkle in the nutmeg, and simmer for about 5 minutes to burn off the fumes. Whisk in the Cheese a small amount at a time until smooth. Remove from heat, and let stand for a minute. (A good time to drink the rest of the beer.) Serve with chunks of sourdough bread.