Lower the pudding carefully into the boiling water and reduce the heat to a fast simmer. Cover with the lid and cook as directed. Keep an eye on the water level and top it up with boiling water (to keep the cooking temperature constant) when necessary. When the cooking time is up, remove the basin from the pan and take off the foil and paper cover. If the pudding is a solid one, test it with a skewer (a fruit pudding, however, may leave the skewer sticky if you hit a piece of fruit) or press the top gently — it should be firm in the centre and well risen. If the pudding is not cooked, re-cover it and continue cooking. Leave for 5 minutes, then invert onto a plate. If the pudding is reluctant to come out of the basin, run a flat-bladed knife around the edge.