Place the ice cream machine into the freezer overnight to chill.

Make the simple syrup first. Bring water and sugar to a boil in a saucepan over medium-high heat. Add mint leaves and reduce heat to medium-low. Cook syrup for 3-4 minutes. Remove from heat and strain syrup into a bowl. Cover and refrigerate at least 4 hours or until ready to use.

Place melon, syrup, mint leaves and lemon juice in a blender. Puree until smooth, about 1 minute. Strain puree into a bowl. Add Midori liquer, cover and refrigerate at least 2 hours. Pour melon puree into ice cream machine and process according to manufacturer's instructions, about 20 minutes. Keep sorbet frozen in freezer until service.

Heat 1 quart of water to a boil in a heavy saucepan. Add asparagus and blanch until just tender, about 3 minutes. Remove asparagus and drain on paper towels. Let asparagus cool to room temperature.

Heat a skillet over medium heat. Brush skillet with a little olive oil. Add prosciutto slices and saute until just crisp, about 30 seconds. Turn prosciutto over and sauté another 30 seconds. Remove prosciutto from skillet.

To serve, wrap each asparagus spear with a slice of prosciutto. (Note: to keep the prosciutto in place, I secure it with a toothpick, just keep the toothpick on the underneath side of the asparagus so it doesn't show). Place a scoop of melon sorbet in a large martini glass. Add two spears of asparagus on either side of sorbet. The asparagus should rest on top of the martini glass. Garnish sorbet with a mint sprig.