Pour all ingredients into a medium sized sauce pan, and bring to a boil.
Reduce heat and simmer for 20 - 30 minutes.
Serve immediately, or store in a sealed container in the refrigerator.
Notes
Guinness the word, the harp logo, and the signature are all registered trademarks. I do not work for them, and I am not paid by them to use their beer in my recipes. I just really, really like cooking with it!
Feel free to use whatever Irish stout that you would like, this is merely my suggestion.