I want to know two things. Can I make suet puddings (savoury) in advance a couple of days? If I use leftovers from the Sunday lunch meat does the pastry take less time to cook?
Steamed suet puddings, such as steak and kidney pudding, are often made with a filling that has been pre-cooked. This reduces the steaming time of the pudding as the filling only needs to be heated through rather than cooked from raw. It also means that you can ensure that the meat in the filling has been cooked until it is properly tender and that the filling is suitable seasoned. So using Sunday lunch leftovers should be fine as a filling.
We would however hesitate on cooking a pudding in advance if it has an already cooked filling. From a food safety point of view, leftovers and pre-cooked foods should only be reheated once. If the leftovers are cooked in a pudding or pie, then left to cool and then reheated again you will breach this guideline and there is always a risk of food poisoning. On a more practical basis it will take almost as long to reheat the pudding as it would to cook it. A steak and kidney pudding with a pre-cooked filling is going to take 1 1/2 to 2 hours to steam if you are using a 1 1/2 - 2 litre pudding basin. To reheat a pudding properly by steaming is going to take almost as long. Some people also feel that suet pastry can be a little tough if it is reaheated.
By all means assemble a pudding a day in advance and keep it in the fridge until you need it, but we suggest steaming it just before you eat it. As steaming is a very gentle cooking method, it won't matter if the pudding is left to steam for slightly longer than first anticipated. So make sure you leave plenty of time to cook the pudding, and make sure that the filling is piping hot all the way through before serving.