1.Preheat oven to 200°C/400°F. Line oven tray with baking paper.
2.To make frangipane, beat butter, extract and sugar in small bowl with electric mixer until creamy. Beat in egg until combined; stir in ground almonds and flour.
3.Cut pastry sheets in half. Place two halves on tray. Spread with frangipane, leaving a 2cm border. Top with peach slices, brush with lemon juice.
4.Gently fold remaining pastry in half lengthways. Cut through folded edge of pastry at 1.5cm intervals, leaving a 2cm border on three open sides. Carefully unfold cut pastry strip, place over peaches. Press edges of pastry together. Brush pastry with egg; sprinkle with sugar.
5.Bake jalousie about 20 minutes or until pastry is browned.
6.Stand jalousie 10 minutes before serving.
Nectarines, apricots or berries would be delicious in place of the peaches. serving suggestion Serve with thick (double) cream.Note