1. Heat oven to 400 degrees. Place turkey in a roasting pan and season with salt and pepper. Roast until golden brown, about 50 to 55 minutes, or until meat thermometer inserted in thickest part registers 185 degrees. Remove from oven; set aside until cool enough to remove skin and slice.

2. Meanwhile, in a small saucepan, combine cranberries, orange juice, sugar, ginger, and orange zest. Bring to a boil over high heat. Reduce heat to medium high and boil until berries begin to pop open, about 5 minutes. Set aside to cool.

3. Slice turkey -- there will be about 1 pound of meat. Place 4 ounces of meat on each of four slices of bread, reserving any extra for another use. Arrange watercress, onion, and 1/2 cup of the conserve on the meat and top with another slice of bread.