Generously grease the pudding basin (mould) with butter and cut a circle of baking paper the same size as the base of the pudding basin. Place the paper circle in the basin; it will stick perfectly to the butter. This will make it easier to get the pudding out of the basin.
Spoon the batter into the pudding basin, then cut another two circles of baking paper with a diameter about 8–10 cm (3¼–4 inches) larger than the top of the basin. Make a narrow fold across the middle to leave room for the paper cover to expand slightly. I like to use two layers of paper. Tie securely around the top of the basin with kitchen string, then cover with foil and tie kitchen string to create a handle so it will be easier to lift the basin out of the pan after steaming.