Shape into an 18 centimeter / 7 inch round and place on a baking tray. Mark into four sections with a sharp knife, cutting to within 1.5 centimeters / 1/2 inch of the bottom. Bake at 200C/390F for 1 hour until nicely browned and hollow sounding when tapped with the back of your fingers. Remove from the oven and wrap in a clean tea towel to cool.