For the aioli, put the garlic cloves onto a chopping board and crush them under the blade or a large knife.
Remove the papery skins, sprinkle the garlic with the salt and work into a smooth paste using the knife blade.
Scrape the garlic paste into a bowl and add the egg yolk.
Whisk together, then very gradually whisk in the olive oil to make a thick mayonnaise –like mixture.
For the fritters, sift the flour, baking powder and a pinch of salt into a mixing bowl. Make a well in the centre and add 300ml/10fl oz water and the wine.
Gradually mix the dry ingredients into the liquid to make a batter, then whisk until you have a thick cream. Fold in the prawns, spring onions and parsley.
Pour ½cm/¼in of olive oil into a large frying pan and place over a high heat. Leave until hot but not smoking, or until a drop of the batter sizzles immediately. (CAUTION: Hot oil can be very dangerous. Do not leave unattended.)
Carefully drop large spoonfuls of the batter into the pan and spread each one out a little with the back of the spoon so they develop lovely thin, crispy edges as they cook. Don’t be tempted to overcrowd the pan – only cook 2-3 at a time.
Cook, turning the fritters over every now and then, for about two minutes or until puffed up and golden brown on both sides.
Remove with a slotted spoon and drain on a tray lined with plenty of kitchen paper. Eat straight away while they are still hot and crisp.