Place cranberries in food processor fitted with steel blade; process until coarsely chopped. Transfer to bowl.
Cut lime with peel, into small chunks. Process until finely diced. Add to cranberries along with sugar and jalapeño. Mix in cilantro.
Refrigerate relish several hours to allow flavors to mellow and blend. If relish gets too juicy drain it. Add liquid to seltzer or other sparkling water for a really zippy drink.
Servings: 2-1/2 cups