Preheat oven to 200°C.
Melt the butter over low heat, add the sour cream and egg and mix well.
Sift the flour, cayenne pepper and salt together and add to butter mixture.
Add the cheese and mix to a soft dough.
Turn dough out on a lightly floured surface and knead lightly.
Pat out with palm of hand to approximately 3 - 4 cm thick.
Shape into a round and mark 6 wedges using a sharp serrated knife.
Do not cut all the way through.
Place on a lightly greased oven tray.
Brush lightly with beaten egg.
Bake for 20 - 25 minutes until golden brown.
Cut into wedges and serve hot with butter and grated cheese.