Peel one of the oranges and reserve the peel.
Chop the peeled orange, the unpeeled orange and the lemon.
Put these into the tomato juice and bring to the boil very slowly; simmer for about 5 minutes.
Let the juice cool with the fruit in it.
Strain, and then squeeze the fruit and add that liquid to the tomato juice.
When quite cold, stir in the Worcestershire sauce, which should give only a mild tang rather than a big bite.
Freeze in a suitable container, and once it starts to set around the edges, whisk it well.
If you do this several times, it will ensure an even texture.
Whisk the egg whites until they are firm but not dry and fold them into the mixture at your last whisking.
This will slow down the speed at which the sorbet melts when you serve it.
Return the sorbet to the freezer but remove it at least 30 minutes before serving.