Using a small ice cream scoop, scoop out balls of raspberry and lemon sorbet, and place on a lined baking sheet, and allow to freeze solid.
Slice ends of watermelon, so that the centre piece is approximately ten centimeters in diameter. Save the watermelon ends for snacking.
Slice centre piece into four even wedges. Using a pairing knife, remove approximately five centimeters of the flesh from the inside of the wedge leaving 2.5 centimeters intact on both sides. Freeze watermelon for one hour.
Stuff chilled watermelon with scoops of sorbet all the way up to the point of the wedge. Enjoy immediately :)