Grease a 1l pudding basin with plenty of butter so the pudding turns out cleanly. Lay a sheet of tin foil just bigger than the basin on a work surface, then lay a sheet of baking parchment the same size over the top. Grease the paper and fold a pleat into the center to allow the pudding room to expand.

In a stand mixer, or with a handheld electric whisk, beat the butter and sugar together until light and fluffy. Add the eggs and beat again, before adding all the dry ingredients and mixing to combine. Add the milk and beat for a further minute before spooning into the pudding basin.

Put the pudding onto an upturned plate in a large, deep pan and pour boiling water into the pan until it reaches halfway up the side of the basin. Cover with a lid, bring to the boil, and then reduce the heat to a gentle simmer. Add more boiling water as necessary, to make sure the pan doesn’t boil dry during the cooking process. Steam for 1 ½ hours, or until the sponge is firm and well risen.

To make the sauce, put the cream and mint chocolates into a small saucepan and heat over a low heat, stirring until the chocolates have melted and the sauce is smooth.