• 1 recipe-quantity of shortcrust pastry
• 285 g/ 10 oz mushrooms
• 30 g/ 1 oz butter
• 2 garlic cloves, chopped
• 1 tbsp olive oil

For the Béchamel Sauce

• 30 g/ 1 oz butter
• 30 g/ 1 oz flour
• 700 ml/ 1¼ pt milk
• 2 tbsp dry sherry
• 1 bay leaf
• salt and pepper
• ¼ nutmeg, grated
• 60 g/ 2 oz Parmesan, grated
• 1 egg yolk

Preheat the oven to 190°C/375°F/ gas 5. Roll out the pastry on a floured surface and use to line a 24-cm / 9½-inch tart tin with a detachable base.

Cover with foil, weight with beans and bake blind for 10 minutes. Remove the weighted foil and continue cooking for about 5 minutes or until the pastry base starts to brown. Remove.

Make the béchamel sauce: make a roux by melting the butter in a heavy pan and stirring in the flour. Cook gently, stirring, for a minute or so. Pour over the milk, whisking, then add the sherry and bay leaf Season with salt, pepper and nutmeg, and cook over a low heat for 20–25 minutes, stirring regularly.

Remove the bay leaf and discard, Whisk in the Parmesan.

In a bowl, whisk the egg yolk, then whisk 2 to 3 tablespoons of the sauce into them. Remove the sauce from the heat and whisk in this mixture.

While the sauce is cooking, sauté the mushrooms in the butter and oil for about 10 minutes. Add the garlic and sauté for another minute, stirring, then stir this into the sauce. Mix thoroughly and pour and spoon into the tart shell.

Put into the oven and immediately lower it to 180°C/ 350°F/gas 4 and bake for 20–25 minutes. Take out of the oven and leave to cool for 5 minutes before removing from the tin.