I use my blender on low, combine cream cheese, grated cheddar and half and half. Add salt, combine. Pour in the Guinness and blend until smooth. Add scallions.Pulse briefly. Add tobasco, to taste. Some like it hot!!!
Chill for at least an hour. When you're ready to eat, bring it to room temperature, it might need a quick stir. Garnish with some chopped parsley and serve with crackers or bread sticks.