Cut butter into flour and salt and either rub between finger tips or pulse in a food processor until the mixture resembles coarse breadcrumbs.
Stir in the yoghurt with a knife until the mixture comes together into a ball,
Cover and leave to rest in the fridge or a cool place for ½ hr.
Roll out on a floured surface into a rough circle to about 4mm in thickness.
Place on a baking tray lined with baking parchment.
Lay the gooseberries over the pastry leaving about a 5 cm boarder.
Sprinkle on all but 1 tbsp of the sugar.
Fold the edges inward over the gooseberries, leaving the centre open.
Brush the pastry edges with milk then sprinkle with the remaining sugar.
Bake at 180℃ (350℉, Gas 4) for 40 minutes when the gooseberries should be soft and the pastry crisp and golden.
Best served warm, but it's pretty good served cold the day after baking too.Please note: calories and other nutritional information are per serving. They're approximate and will depend on exact ingredients used.