Fill mould or bowl three-quarters full (or even less if pudding mixture is very light and spongy) to allow the mixture to rise.
Cover the top of the mould or bowl with a piece of buttered paper, twisting it on so that it does not fall down the sides; place it in a saucepan with just enough hot water to reach half-way up the mould; put a tight-fitting lid on the pan, and keep the water at simmering point until the pudding is cooked. If water boils down, add more hot water. Custard puddings must be steamed very slowly and carefully, as extreme heat will curdle the eggs and make the pudding watery. With the lighter puddings, I always put a saucer or old plate at the bottom of the saucepan to raise the pudding mould a little away from the direct heat of the stove.