Punch down and separate into two balls. Flatten each ball into a rectangular shape, then roll into a long loaf. Let them rise on an oiled cookie sheet until almost double.
Put a pan of boiling water on the bottom of a 205C/400F oven and bake. After 15 minutes, reduce heat to 180C/350F for about 30 minutes. 5 minutes before bread is done, brush loaves with melted margarine.