Place frozen vegetables in microwave safe bowl and cook on high for 1min. Drain and allow to cool.

Place vegetables, cooked chicken, cheese, mayonnaise, seasonings into bowl and mix well.

Cut each sheet of pastry into 4 even squares. Brush edges lightly with water. Spoon mixture onto one half of square. Fold pastry over to form a triangle. Seal edges with a fork.

Place on a baking tray. Cut a steam vent with knife. Brush lightly with egg yolk. Sprinkle with sesame seeds.

Bake in hot oven (200C) for 15-20 mins or until golden and puffed