The method is simple: you just roll some tasty morsels into a slice of gammon and simply allow your taste buds to set the limits for what you can use.
Here are three alternatives that are all based on having one slice of gammon with fruit and root vegetables cut into ½ x 1 inch sticks. You can decorate them by sticking a dill flower or something similar into the tops of the rolls. You can either trim the rolls at the base and serve them standing up, or simply place them neatly on a plate.