Sea Scallop Pie

* Or 6 scallops and an equal amount of any white fish. Or more
scallops, if you like.

Clean the scallops and cut in half, then simmer in the milk for 15
minutes. Strain, reserving the liquid. Heat 1 tablespoon of the butter
and stir in the flour, cook for about a minute, stirring, then add the
milk gradually, stirring all the time to avoid lumps. Season with salt
and pepper, add the sliced mushrooms and simmer for about 10 minutes
longer; then add the sherry or wine and finally the scallops. When hot,
transfer to an ovenproof dish and cover with mashed potatoes, making sure
they cover the fish right to the edges. Dot with the remaining butter and
bake in a moderate oven, 350F, for 20-30 minutes, or until the top is
turning brown.