The sugars in the rum and pineapple combine to make a delicious sweet and salty ham, perfect for your Easter or Christmas celebration. Reserve the pan drippings for a quick sauce that you can pour over your finished ham before serving.
Preheat the oven to 300 degrees F. Soak the pineapple slices in the orange juice for at least 10 minutes.
Place the ham in a roasting pan and spread the Dijon mustard evenly on the ham to coat. Sprinkle the brown sugar over the ham, and then place the pineapple slices over the ham, securing them with the cloves. Pour the orange juice and ½ of the rum in the pan.
Bake the ham in the oven for about an hour. The brown sugar and pineapples should just be starting to brown. Remove the ham from the oven, and pour the remaining rum over top of the ham. Light the rum with a match to flambé the ham.
Continue baking the ham for an additional hour or until the internal temperature of the ham reaches 140 degrees F. Transfer the pan drippings to a sauce pan. Combine the water and cornstarch and whisk the cornstarch mixture into the pan drippings. Cook for about 5 minutes or until the pan sauce has thickened. Allow the ham to rest for 10 to 20 minutes before slicing and serving with pan sauce.