Swede, Mushroom, Gruyere, Thyme
|Source||Nigel Slater. https://www.nigelslater.com/Home|
A favorite from Nigel Slater's Greenfeast: autumn, winter
Make the pastry: put both flours and the thyme leaves in a large bowl, cut the 150g of butter into small pieces, then add it with the salt to the flour and rub together with your fingertips until you have a bread-crumb-like consistency. Introduce enough cold water to produce a soft, rollable dough. Alternatively, you could make this in a food processor. Turn out onto a floured work surface, pat into a ball, flatten the top, then wrap in baking parchment and refrigerate for 30 minutes.
Set the oven at 200C/Gas 6. Place an upturned baking sheet or pizza stone in the oven to heat up. Peel and roughly chop the onion then let it soften in 30g of the butter over medium heat in a large, wide pan. Peel the swede, cut it in half lengthways, then cut each half into quarters. Slice each quarter thinly. Remove the onion from the pan - it should be pale gold and translucent. Add the pieces of swede to the pan, adding more butter if necessary, turning them as they brighten and soften. Thinly slice the mushrooms, then add them to the pan, with the remaining butter and cook till pale gold. Grate the Gruyere into a large bowl, then add the swede, onions and muchrooms. Season generously with black pepper.
On the floured board, roll the pastry out into a large, rough-edged cricle approximately 30cm in diameter and transfer to a parchment-lined or flour-dusted baking sheet. Pile the filling in the center of the pastry, leaving a wide gap of bare pastry round the edge. Fold the edges of the pastry over the filling, leaving the middle open. Brush the edges with beaten egg, then place the whole baking sheet on top of the hot sheet or stone in the oven and cook for 25 minutes, till the pastry is pale gold and the filling has crisped on top. Leave to settle for 10 minutes before slicing.
Good cold too and can be sliced and tucked inside a lunchbox or taken on a picnic.