In a medium saucepan, combine the onion, sugar, wine, ginger, lemon peel, and salt. Bring to a boil over high heat, stirring to dissolve the sugar. Reduce the heat to maintain a simmer, then simmer for 15 minutes. Stir in the cranberries and pears, and simmer until the cranberries and onion have softened, about 20 minutes. The sauce will become a rich scarlet color. Remove and discard the lemon peel. Let cool to room temperature before serving. Store in an airtight container in the refrigerator for up to 2 weeks.
