From 1922:

Make a nice rice pudding, baking it as slowly as possible for four hours. Also prepare rhubarb, boiling the fruit juice well to reduce it. When cold invert the pudding into a deep crystal dish, and around it place the rhubarb and its juice. Have ready a pint of really thick cold boiled custard flavoured with vanilla, and pour it over the whole. Even when the baking dish is thickly buttered the pudding may stick and break at the bottom, but it is easily pressed together when turned out.