I'm sure you could use a steamer as long as you kept it topped up with water. As for the microwave I wouldn't use the microwave beacuse it would cook the pudding too quickly and you'd end up with something resembling rubber. You would usually steam a pudding for up to 10 hours so it does necessiate a slow cooking process. You can however do it in the oven. To do this you put the pudding in a deep tray which you fill well below the top of the pudding bowl. You then use tin foil to completely seal the tray over the bowl. This method is a lot easier and creates a lot less steam in your kitchen.