I have been meaning to post this mushroom tart recipe for ages. It was given to me by my mother’s friend Sarah, who was an excellent cook; her hand-written recipe has been pasted into my recipe book for forty years now. Although Sarah was vegetarian herself, she also cooked meat and fish for her family and friends, and her food was always perfectly seasoned even though she never tasted the meat dishes.
As the tart uses puff pastry, it is a bit of an indulgence, but it does turn an ordinary punnet of button mushrooms into something special. I sometimes use chestnut mushrooms or a mixture of button and field mushrooms. It is important to cook the mushrooms ahead of time and let them cool down as otherwise the heat can soften the pastry which makes it difficult to manage. Tarragon works particularly well here, but parsley is nice too if you don’t have any tarragon, in which case you could add a crushed clove of garlic to the mixture too.
Sarah recommended Saxby butter puff pastry if you can get it. Rolling the pastry yourself will give a thinner crust, but a ready-rolled sheet is fine if you prefer. This serves 3-4, depending on how many sides you serve with it.
350g button or chestnut mushrooms
1 tsp plain flour
1 tbsp sherry or white wine
150ml single or sour cream
huge pinch of tarragon or parsley
200g (or a ready-rolled sheet) all-butter puff pastry
1 egg beaten with a little milk
Slice the mushrooms very thinly. Melt the butter in a frying pan and sweat the mushrooms in the butter over a gentle heat until they are ‘slug-like’, which will take 5-10 minutes.
Sprinkle on the teaspoon of flour and cook for a few more minutes. Stir in the cream, herbs and sherry and season with salt and black pepper. Cook for another couple of minutes. Then leave the mixture to cool, preferably for an hour.
When you are ready to bake the tart put the oven on to heat to 210°C. Roll out the pastry very thinly into a large oblong (or unroll the ready-rolled sheet) and place half on a baking sheet, with the other half off the edge. It helps to put some baking parchment on the bench to stop this part of the pastry sticking to it. Paint the edge of the pastry with the egg wash. Spoon the cool mushroom mixture onto the half of the pastry which is on the baking sheet and carefully fold the other half over the top.
Seal the edges very firmly with a fork or crimp the edges together with your fingers rather as you would for a pasty. As you can see below, my effort was far from neat this time – I had taken the pastry out of the fridge a bit too early and it was not being co-operative. Paint the top with egg wash and make two or three diagonal slashes in the top for the steam to escape.
Bake for 25-30 minutes in the oven, until the tart is puffed up and golden brown. Serve with salad or a green vegetable such as chard or broccoli, and new potatoes if you wish.