- STEP 1
Pre-heat a fan forced oven to 180 degrees celsius. Sift the flour and salt into a bowl. Cut the chilled butter into cubes and cut into the flour with a knife before rubbing into the flour with your finger tips until it resembles breadcrumbs. Once combined, add one tablespoon of cold water and combine into a dough. Knead lightly for two minutes until elastic before wrapping in plastic and leaving to rest for half an hour.
- STEP 2
Flour a large clean surface and flour your rolling pin. Place the flat of your hands lightly on each end of the rolling pin and begin to roll the dough backwards and forwards rather than side to side. Do this as evenly as possible, re-dusting the pin and the surface very lightly with flour if the pastry is sticking. Give the pastry quarter-turns as it expands and, provided you continue to roll backwards and forwards and not side-to-side, it will roll out into a circle that will keep its shape and not shrink as it cooks.
- STEP 3
Carefully roll the pastry around the rolling pin and roll out over a quiche tin. Using your fingers, gently press the pastry into the tin to line the base and sides making sure you ease the pastry into the corners and press it against the sides without stretching it, leaving the edge of the pastry overhanging the sides. Prick the bottom of the tart with a fork over the base approximately ten times. Fill the pastry case with a round of baking paper and add baking beans or rice to weigh it down. Bake for 15 mins, then carefully remove the paper and beans before cooking the pastry for 5 mins more (this is called baking blind).
- STEP 4
Finely chop the onion, garlic chestnuts and mushrooms. Heat 2 tbs of olive oil in a large frying over a high heat before adding the onions, stirring constantly until caramelised. Add the garlic, mushrooms, thyme and chestnuts, cooking until mushrooms are golden brown. Season to taste and leave to cool.
- STEP 5
Add the mushroom mix to the pastry case and place in the oven for 20 minutes. To serve, drizzle with truffle oil and sprinkle with thyme.