Sauce In Fish Pie

Asked by Mary123456. Answered on 4th October 2020

Full question

I often make the Nursery Fish Pie with semi-skimmed milk but sometimes my sauce curdles when I heat the pie in the oven - why? Otherwise it's wonderful.

Nursery Fish Pie

By Nigella

Our answer

Nigella's {Nursery Fish Pie](https://www.nigella.com/recipes/nursery-fish-pie) (from FEAST) is a traditional British fish pie made with poached fish in a white (bechamel) sauce and topped with mashed potato. The sauce is made with the fish-poaching liquid and the recipe suggests using full-fat (whole milk). This milk should not curdle as it has a high enough fat content to stay emulsified.

Usually semi-skimmed (reduced fat) milk with a fat content of 2% also stays smooth in this type of dish. If, however, you have used skimmed (non-fat) milk or the type that only has 1% fat, then the sauce can curdle as the water content is so high. Otherwise we wonder if the pie is being slightly overheated. In this case the fish will overcook and extra water will be squeezed out, leaving a watery section in the pie. It may help to reduce the oven to 180C/160Fan/350F, as ovens vary, and heat the pie a little more gently. Make sure that the pie is piping hot in the centre before removing it from the oven.