In a medium saucepan, combine the onion, serrano chilies, brown sugar, red wine, lemon zest, coriander 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 apples, and simmer for 20 minutes or until the cranberries and onion have softened. The sauce will become a rich scarlet color.