About this recipe:Although the pie is traditionally Cornish I'm not sure how authentic this is. However it is the one I remember from my childhood and which I rediscovered in my mother's very old and tatty recipe book. I have tweaked it a bit here and there and I'm flexible about the vegetable filling.
Prepare the sardines for the pie by gutting them. Remove the tail but leave the head attached. Remove the backbone and snip off as close to the head as possible. Wash well under cold running water. Set aside.
To make the sauce, heat the stock and then add the mascarpone and cream. Bring to the boil and then set to simmer. Put the mustard powder and the turmeric in a small bowl. Add a spoonful of the sauce and mix to a smooth paste. Add another spoonful and mix again. Pour back into the sauce and stir well. Season with salt and pepper and then taste. Add more mustard if required. Remove from the heat and allow to cool.
Fry the onion and garlic in a drizzle of oil till soft. Remove from heat.
In a bowl combine the breadcrumbs and thyme and then add enough milk to make a stuffing. Mix in the onion and garlic, and then the zest and juice of a lemon. Season and mix well.
Use this stuffing to fill the sardines.
Roll out the pastry and use the pie dish to cut a piece the right size for the lid. Cut several strips about 1.25cm (1/2 in) wide to go round the edge.
Wet the edge of the dish and place strips of pastry around the rim and then lay the stuffed sardines into the dish with the heads sticking above the rim.
Add the egg and beans then pour the cooled sauce over.
Brush the pastry edging with water and then lay the pastry lid on top. Crimp around the rim. Where the pastry lid meets the fish heads, snip the pastry with scissors and bend it around. Brush with beaten egg.
Bake for about 30 minutes at 180 C / Gas 4, till the pastry is a nice golden brown.
Other versions can be made using mackerel or pilchards, but sardines are traditionally used. I used green beans in this pie because that was what I had to hand, but you could use peas or carrots or anything else seasonal. Whatever you use, cut fairly small and lightly steam until tender.