Immigrant’s Fish Pie

A more sophisticated version of an early Anglo-Jewish dish which provided a tasty but economical meal for immigrant families, who were taught the rudiments of British cooking in an effort to Anglicise them. This version, with its filling of three varieties of fish folded into a delicious sauce and topped with fluffy mashed potatoes, is ideal to serve as the main dish at an informal supper. It can be prepared up to 24 hours in advance, then baked as required.