Recipe adapted from the Produce for Better Health Foundation.
Place peppercorns on a chopping block. Use the bottom of a heavy saucepan to crush the peppercorns. Place the saucepan over the peppercorns and press firmly down. Crush peppercorns into a semi-coarse texture.
Combine the ground peppercorns with finely chopped mint.
In a large bowl, toss spice mixture gently but thoroughly with watermelon cubes.
Chill this mixture until ready to serve.
Spoon into 4 individual serving glasses or bowls and serve with a fresh mint leaf.