Mushroom tart

Instructions

1. To make the pastry, sift the flour and salt into a bowl and add half the butter. Using your fingertips, gently and swiftly rub the butter into the flour until it resembles coarse breadcrumbs. Add the rest of the butter and rub in until the mixture starts to form clumps the size of small peas. Make a well in the centre of the dry ingredients. 
2. In a small bowl, mix together the beaten egg, lemon juice and water, then gradually pour into the dry ingredients, a little at a time, using a knife to help form a dough – you may not need all the liquid. Turn out the dough onto a floured board and knead lightly until smooth. Shape into a ball, wrap in cling film and refrigerate for at least 30 minutes.
3. Preheat the oven to 200°C (400°F/gas mark 6). Roll out the pastry on a lightly floured surface to a 5mm thickness and carefully press  into a 22cm tart tin, leaving the edges hanging over. Line the pastry case with baking parchment, fill with dried beans or rice and blind bake for about 15 minutes until the pastry is set.
4. Meanwhile, for the filling, melt the butter in a large non-stick frying pan until foaming and fry the shallots and mushrooms for 4–5 minutes until deep golden brown.
5. Remove the tart case from the oven and lift out the baking paper and beans, then trim the overhanging pastry edges.
6. Whisk the eggs and cream together in a bowl, season with salt and pepper and pour into the tart case. Gently and evenly spoon in the mushroom mixture, then bake the tart for 25–30 minutes until golden and set.