Heat up the port with the sugar until the sugar has dissolved, and add salt and freshly ground black pepper to taste.
Remove the gelatin sheets from the water and place into the pan with the port and then stir until dissolved.
Remove the pan from the heat and pour the port solution into a canning jar or bowl, before covering and allowing to cool. Transfer to the refrigerator and allow to set (about 5 or 6 hours) before enjoying.
Gelatin powder can easily be used in place of gelatin sheets - simply follow the instructions on the packet to replace it.