In French, what we call a pie is called une tourte. It's different from une tarte in that it has a top crust as well as a bottom crust. One famous example is called Tourte Lorraine, from the Lorraine region in eastern France. It's a meat pie filled with veal, pork, herbs, and cream.
For the past couple of weeks, Walt has been making puff pastry — pâte feuilletée. He keeps saying how easy it is to make, and I keep saying, "Make more." This week he made a big batch, and a couple of days ago we had another Galette des Rois (a puff-pastry pie filled with almond cream).
Then Walt said, "Well, what about making a tourte, a savory galette." That wasn't a bad idea. Shrimp and mushrooms? Cream sauce?
Once you have the pastry, it's pretty easy. Wash and slice about half a pound, 250 grams, of button mushrooms. Sauté them slowly in butter with a diced shallot or onion. When they are done, take them out of the pan, add some more butter if necessary, and slowly sauté about two dozen little shrimp (prawns or crevettes). First, of course, you have to peel and de-vein the shrimp.
Don't throw the shrimp shells away. Put them in a sauce pan with just enough water to cover them. Add a quarter-cup of white wine, some salt and pepper. Then simmer the shells to make a stock. Let it reduce by about half. Strain that stock and it can be the basis for the cream sauce you'll use to make the savory pie.
With the the mushrooms and the shrimp lightly cooked and held in reserve, make the cream sauce. Melt a tablespoon of butter in a pan. Add a tablespoon of flour, stir it in well, and cook it on medium heat for a minute or two. Then add the shrimp-shell stock,beating it in as it thickens. Then add enough milk and cream — the more cream the richer the sauce will be, of course — and keep stirring to make a thick sauce. Keep it thick.
Lightly season everything as you go with salt and pepper. You can add some parsley, oregano, or chervil to the sauce — or whatever herbs or spices you want.
Then you just have to put the pie together. Cut circles out of the pastry. On the bottom crust, spread a thin layer of the cream sauce. Arrange the mushrooms on top of that. Add a little more sauce if you want, and then make a layer of shrimp over all. If you want, you can cut the shrimp in half lengthwise before putting them on top of the mushrooms, to make them thinner and approximate the same shape as the mushrooms.
With both layers of the filling in place, spoon some more sauce over the top. Don't overdo it, because you don't want it to come running out of the pie as it cooks. That's why it needs to be thick.
Put on the top crust. Seal the edges with some beaten egg, and then decorate it if you are so inclined. Paint the top with some more beaten egg, and then bake the pie in a hot oven for 30 to 45 minutes, until it is golden brown. The filling is all already cooked, so you don't have to worry about that. It will heat through as the pastry shell cooks.
Let the pie rest for 10 minutes or so when it comes out of the oven. It'll be easier to cut after it rests. Thin the remaining cream sauce a little with milk and serve it on the side.
You could make the same pie with poached chicken breast. Or with mushrooms and vegetables, and no meat at all. Anything that would be good in a cream sauce would be good in this pie.