For the melon with Parma ham, cut the melon in half and scrape out the seeds. Use a baller to prick balls out of the melon flesh.
For the passion fruit salad dressing, mix all ingredients well and season to taste.
Divide the melon balls evenly among 4 plates and place 2 slices of Parma ham on each. Drizzle the melon with Parma ham with the passion fruit salad sauce.