Soak the cranberries in the port for an hour.
Melt the butter in a pan over a medium heat. Add the onion and bacon and cook gently until the onion is tender and the bacon is cooked.
Add the garlic and fry for another minute.
Remove from the heat to cool slightly, then pour into a bowl.
Add all of the remaining ingredients, including the cranberries and port, and mix well, adding enough egg to bind to form a thick paste.
Fry a small knob of the mixture to test for seasoning, and add salt and freshly ground black pepper to the mixture according to taste. The stuffing is now ready to use, to stuff turkey or chicken.