We dusted off the ice cream maker yesterday and tried our hands at some mango sorbet. Yum. We didn't do all the fancy freezing in the shell bit, but I'm sure it'd be pretty.
4 ripe mangoes (about 3 1/2 pounds total)
1 cup Simple Syrup (equal parts water and sugar)
3 tablespoons fresh lime juice, or to taste
Using a sharp knife, remove the 2 flat sides of each mango, cutting lengthwise alongside pit and cutting as close to pit as possible so that mango flesh is in 2 large pieces. With a spoon carefully scoop flesh from mango sides into a blender, leaving shells intact. With a knife cut remaining flesh from pit and add to blender. Add syrup and lime juice to blender and purée until smooth. Put mango shells on baking sheet and freeze while making sorbet. Freeze mango purée in an ice-cream maker. Scoop sorbet into frozen shells, mounding slightly, and smooth surfaces. Freeze filled mango shells at least 6 hours, or until frozen hard. Frozen sorbets in shells may be wrapped individually in plastic wrap and kept in freezer 1 week.