The rhubarb cuts nicely through the custard richness of this pudding.
Bread: use a good firm bread such as French. Even challah might be nice. Milk: You should probably use a higher fat milk rather than a skim. If you use a low-fat milk, you will probably have to replace some of it with a cream, or compensate by adding an extra egg in order to get the pudding to set. But you could try it with a low-fat milk if you cook it slower and longer. The ovenproof dish you use needs to hold about 6 cups in volume (3 pints / 1.8 litres). You will also need a larger dish (such as a roasting pan), that this ovenproof dish will fit inside of -- this pan will hold water to moderate the cooking temperature of the pudding, acting as a "water bath".