A fewtablespoonsof a gluten-free flour blend for rolling
1eggbeaten for the egg wash
For the filling:
100gvacuum packed chestnutsroughly chopped
¼teaspoonground white pepper
To make the pastry
In a large mixing bowl combine the flours, chia seeds and salt.
Rub the butter into the flour in between your fingertips so it resembles very rough breadcrumbs then stir in the beaten egg with a fork.
Add the water 1 tablespoon at a time and start to bring the dough together with a pastry scraper. It should start to form quite quickly.
Tip the dough onto the work surface and bring the ball into a round ball. You want the pastry to still be a little sticky.
Wrap the pastry in greaseproof paper and flatten the ball slightly.
Place in the fridge for 30 minutes to chill.
Pre-heat the oven to 180°C.
Dust the work surface with a gluten-free flour blend then roll the pastry out into a circle large enough to line a 25cm tart tin.
Once you have lined the pastry in the tin and neatened the edges with a knife, place greaseproof paper over the pastry, so it comes up the sides, then fill the tin with baking beans.
Place the tart tin in the oven for 20 minutes. Take out of the oven then remove the baking beans and parchment and brush the surface of the pastry with the beaten egg.
Place back in the oven for a final five minutes to seal the pastry. Remove from the oven and leave to cool to room temperature before adding the filling.
To make the filling
First prepare the onions by adding them into a saucepan along with the salted butter. Cook on a low heat for 25-30 minutes until the onions are completely soft, translucent and just beginning to caramelise around the edges. Leave to cool for half an hour before adding to the other ingredients.
Pre-heat oven to 180°C.
Whisk the eggs, egg yolks and crème fraiche together, then add the stilton, chestnuts, caramelised onions, salt and pepper. Do reserve some of the stilton and chestnuts for crumbling onto the top.
Pour the filling into the ready-baked pastry case and then dot the remaining stilton, chestnuts and cranberry sauce on top.
Place the tart in the oven and bake for 30 minutes.
You can either eat the tart straightaway hot from the oven or leave to come to room temperature where the tart will firm up a little more.