To make the pastry, pulse the butter and flour in a food processor until the mixture resembles breadcrumbs. Add Bulla Sour Cream and pulse until the dough just forms a ball. Wrap dough in cling wrap and refrigerate for 20 minutes.
Preheat oven to 180°C (160°C fan forced).
Combine peaches, nectarines, raspberries and sugar in a bowl.
On a lightly floured surface, roll pastry out to a rough circle, around 35cm diameter.
Place on a lined baking tray. Sprinkle over the almond meal, leaving a 5cm border. Pile the fruit filling in the middle, spreading over the almond meal. Fold the pastry edges over the filling, pressing lightly to seal.
Brush pastry with egg yolk and sprinkle with raw sugar.
Bake tart for 35-45 minutes, until pastry is golden and fruit is cooked.
Serve straight from the oven topped with a heaped spoonful of Bulla Dollop Thick Cream.