Heat the olive oil in a skillet over a medium/high heat. Add the bacon slices. Cook the bacon through until crisp and golden all over. Remove from the skillet with a slotted spoon and set to one side. Once cooled enough to handle, roughly chop/crumble the cooked bacon into small chunks.
Finely chop the onion. Add the onion to the skillet used to cook the bacon. Set over a low/medium heat and sweat gently for a minute or two until tender and fragrant. Set to one side with the bacon.
Add the cranberries, cinnamon, ginger, balsamic vinegar, erythritol, salt, pepper and 3/4 cup of water to a small saucepan. Set over a medium heat and bring up to a gentle boil. Reduce to a simmer and continue to cook gently for 10 minutes until the cranberries are plump and rehydrated. Stir often and add a splash more water if the pan looks a little dry.
Add the remaining water and xanthan gum to the saucepan. Stir well to combine. Cook gently for a few minutes more until the sauce has thickened and you have a jam-like consistency. Taste and adjust seasonings as required, adding more spices or sweetener as needed.
Crumble in the bacon pieces and add the cooked onion. Stir through well to combine. Allow the sauce to cool. Serve with your preferred Keto mains and sides.