You can thicken the peaches with cornstarch, instead of reducing the juices, but my method is lighter and the flavour is more intense. The pastry is rich and delicious.
1 cup flour
1 teaspoon salt
1/3 cup butter
1/3 cup mascarpone cheese
1 pound peaches
1/3 cup peach or apricot jam
1 tablespoon lemon juice
1 egg, beaten
1 tablespoon sugar
Combine flour, salt and butter in a food processor and pulse together until mixture resembles coarse crumbs. Add mascarpone and pulse until well combined. Remove from processor and gently knead to bring dough together into a ball. Chill for 30 minutes.
Divide dough into 4 equal pieces. Roll each piece out into a 6-inch square on a floured board. Chill until needed.
Preheat oven to 375 F.
Bring a pot of water to boil and add peaches. Boil for 30 seconds, remove from heat and slip off skins. Cut peaches into ¾-inch chunks.
Place jam and peaches in a pot over medium heat. Bring to a gentle simmer and cook, stirring frequently, for 6 to 8 minutes or until peaches are cooked.
Strain mixture, reserving fruit and juices separately. Return juices to pot, bring to a boil and cook for 8 minutes or until juices are the consistency of jam and have caramelized slightly. Return peaches to mixture. Stir in lemon juice and let cool.
Place ¼ cup of peach mixture onto each pastry square. Moisten edges with cold water and fold pastry in half to make triangles, pressing edges together with the tines of a fork to seal. Use a knife to trim pastry edges.
Place turnovers on a parchment-lined baking sheet and brush with beaten egg and sprinkle with sugar. Cut a few slits on top to allow steam to escape.
Bake for 22 to 25 minutes or until pastry is golden and filling is hot.
Serve warm or cold with ice cream. Makes 4 turnovers.