Mix all the ingredients together, except the egg and milk.
Add the beaten egg and milk and mix well. (I do this in a mixer but you can do it by hand, no problem.)
Put the mixture in the basin, cover with tin foil or a cloth, and put the basin in a pan with water half-way up the sides of the basin. Bring the water to a boil, put on a tight-fitting lid, and simmer for 3 hours, remembering to top up with (add more) boiling water now and then.
