STEP 1 Put the fish in the fish stock in a pan & bring to a simmer and put the eggs on to hard boil, 8 to 10 minutes should do, but not so much they go grey.
STEP 2 Meanwhile melt the butter in a heavy based pan, add the ﬂour and cook gently until you have the texture of sandy breadcrumbs – this is called a ‘roux’.
STEP 3 Now ladle in a little of the stock at a time stirring vigorously between each to knock out any lumps. Keep going until you have a sauce consistency you are happy with - do not necessarily add all the stock.
STEP 4 Peel & slice the eggs
STEP 5 Gently mix together the fish with the sauce, mustard, dill, cream, anchovy sauce. Taste & season with a little pepper, the anchovy should have done for the saltiness. Put the mix into your bowl or bowls and allow to cool.
STEP 6 Later, beat the egg yolk into the mash then spread over the pie.
STEP 7 Top with cheese & bake in a medium (170°C) oven.
STEP 8 Individual pies may take only 15 to 20 minutes and a larger one more -bon appetit!