1.Preheat oven to 200°C (180°C fan-forced).
2.Cut pastry into four squares; place on an oiled oven tray. Bake 15 minutes or until browned lightly and crisp.
3.Meanwhile, heat oil in a large frying pan over high heat. Coarsely chop chicken; cook chicken, in batches, until browned.
4.Add butter, garlic, leek and bacon to pan; cook, stirring, until leek softens. Stir in mustard and wine; bring to the boil. Reduce heat; simmer, uncovered, 2 minutes or until reduced by half. Stir in cream; simmer, uncovered, until sauce thickens slightly. Season to taste.
5.To serve, top chicken mixture with pastry squares.