Place flour, salt,sugar and yeast in a bowl. Slowly mix in enough water to form soft dough. Knead on a lightly floured surface until it becomes elastic. Chill for 1 hour.

Roll out a rectangle tht measures 30x 15cm(12x16in). Squash the butter until it is 1cm(1/2in) thick. Place the butter in the center of the dough. Fold the dough over so the butter is encased,and chill fo 1 hour.

Roll out the dough on lightly floured surface to a 30x15cm rectangle. Fold the right third over the center, then fold the left third over the top so you have 3 layers to your dough. Chill for 1 hour

Repeat the folding and chilling process twice more. Add grated cheese in between folding.

Roll out the dough to a 3mm (1/8in) thick square. Cut into 10x10cm(4x4in) squares, then cut diagonally to make triangles of dough. Holding the point at either end of the longer length, roll the dough towards you, pulling the point. Place on oiled baking trays, leaving plenty of space between each and curve them into crescent shapes. Leave for 1 hour,or until double in size.

Preheate oven to 240C (475F/gas9). Brush the croissant with the beaten egg and bake for 10 min, then reduce oven to 190C (375F/gas5) and bake for 10-15 mins or until golden brown. Cool on a wire rack.