Melt the butter in a frying pan, add the minced shallots, and cook for a couple of minutes to soften. Remove the shallots from the pan with a slotted spoon.
Cut the eels into 2-inch slices and flatten slightly. Add to the pan and fry in the butter for a minute or two just to stiffen. Lay the pieces of eel in a pie dish, and add the shallots, mushrooms, parsley, fennel, lemon zest, and nutmeg, salt, and pepper to taste. Mix gently together.
For the sauce, melt the butter in a clean saucepan, add the flour, and cook together for a few minutes, stirring constantly. Gradually add the fish stock and white wine, whisking well. Slowly bring to a gentle boil and cook for 2-3 minutes. Season with a very little pepper and salt. If necessary, add a little more wine or stock, as the sauce should not be too thick. Pour the sauce over the eel and leave to cool.
When the filling is cold, cover with the pastry.
© 1999 Jennifer Paterson and Clarissa Dickson Wright estate. All rights reserved.