4. Line the base of a 2-litre pudding basin with baking paper and grease the sides. Pour the mixture into the basin and smooth the top. Cover with a double thickness of baking paper and tie tightly. Do the same with tinfoil and tie again.
5. Place the pudding in a large pot. Fill halfway up the sides with warm water. Bring to a boil then lower to a simmer for 4 hours. Add more hot water as required.
The pudding is cooked when a skewer inserted into the centre comes out clean.