(adapted from a cooking class with Roberto Donna)
Serves 8.
8 oranges (about 6 cups freshly squeezed juice)
sugar (to taste)
3 Tbls. Grand Marnier
fresh mint
Wash the oranges and cut in half. Juice the oranges with an electric juicer or manually - being careful not to squeeze the shells too much, as the shells will be used for serving the granita. You should have about 6 cups of juice.
Remove the remaining flesh from the inside of each shell and shave a small amount of the peel from the bottom so the shells stand easily by themselves (be careful not to puncture the bottom). Place the clean shells on a baking sheet or in a bowl and put in the freezer.
Mix the juice, sugar (to taste), and Grand Marnier in a bowl. Mix and pour onto a baking sheet to form a thin layer of liquid (it should not be more than 1 inch). Place the baking sheet in the freezer for about 2-3 hours until solid, scraping the granita with a fork every hour.
To serve, scoop the frozen granita into the orange shells and garnish with slivers of fresh mint.