Place the gooseberries in a saucepan with the sugar and 300 ml (10 fl oz) of water. Bring to the boil, then cover and simmer for 25 minutes, or until the fruit has softened to a pulp.
Purée the gooseberry pulp in a food processor or with a hand-held mixer, then strain it through a fine sieve, discarding the pips. Stir in the wine and lemon juice and leave it to cool.
Transfer the cooled mixture to a shallow, freezerproof plastic container, cover and freeze for 1 hour.
Use a fork to mash into the liquid any ice crystals that have formed around the rim and base, then cover and return to the freezer for a further 4 hours, beating in any ice crystals every hour. Serve the granita in glasses as soon as it is ready.
Variation: if gooseberries are unavailable use seedless green grapes.
Tip: if you want to make the mixture in advance, keep it chilled in the refrigerator until it is time to start the freezing process at Step 3.