Combine ginger, garlic vinegar, sugar and cayenne in a small pot. Bring to a simmer on medium heat about 15 minutes or until there are about 4 tablespoons of liquid left. Add can of cranberry sauce, salt, and pepper. Mix and bring to a simmer.
Lumps are ok.
Simmer on a gentle heat for about 10 minutes. Cool, store and refrigerate. It will keep for several days.