Roll out the puff pastry to a 5mm thickness. Cut into rectangles 6x15cm.
Combine the cheese, spring onions and seasoning in a bowl and mix well. Spoon a little dollop of cheese mixture in one half of the rectangle, then using a little egg, brush the sides before folding over to seal. Transfer to a baking tray and brush the tops with beaten egg.
Bake in the preheated oven until puffed up and golden brown, about 10 minutes. Remove from the oven and serve warm or allow to cool before serving.