2 large oranges (choose the most aesthetically pleasing ones you can find)
4 tbsp icing sugar
Cut the oranges in half across the middle and carefully scoop out the flesh using a grapefruit knife. Use the tip of the knife to extract as much as possible from the sides without damaging the skin. Place all the flesh and juice with the icing sugar in a food processor and blend until smooth. Pour into a plastic tub and place in the freezer.
Check to see if the orange skins can stand by themselves as they are to be used to serve the sorbet. If not, slice a bit off the bottom to flatten it out. Place them in the freezer.
After about 3 hours, remove the orange mix and put back in the food processor. Blend again (this gets rid of a lot of ice crystals). Spoon the blended mix into the frozen orange skins and freeze again.
About ten minutes before eating, remove the oranges from the freezer and allow to defrost a little before serving.