Supper Onion Pie Dough

Our answer

Nigella's Onion Supper Pie (from HOW TO BE A DOMESTIC GODDESS) has an easy to make dough base that is similar to a scone dough, but with less raising agent. Usually when you add liquid to anything with a raising agent then the agent activates and if left to stand for too long it will expire. However in this particular case case the amount of baking powder is quite low and the dough does not need to rise much, so if you use a double action baking powder (where the baking powder is activated for a second time in the heat of the oven) then you should be able to make the dough in advance. Just bear in mind that the dough may be a little more dense.

Almost all baking powders sold in the UK and the US are double action baking powder and so should be fine to use for the pie dough. We would also suggest that you cook the onions, let them cool and, when cold, put them in the pie dish then mix the dough, form the dough into a circle and put into the pie dish. Cover the pie dish tightly with clingfilm (plastic wrap) before refrigerating it. If you chill the dough straight after making then it may become too stiff to press or roll out into a circle easily. If you are baking the pie from chilled then you may need to allow an extra 5 minutes of baking time after you lower the temperature of the oven, to make sure that the crust is crisp and the onions are piping hot.