Heat the oven to 180°C
First, make the pastry. Pulse the flour, butter and salt in a food processor to the consistency of breadcrumbs. With the motor running, steadily add the water, stopping as soon as the dough comes together. Remove the dough, knead it a couple of times, then wrap it in parchment and chill it in the fridge for at least 30 minutes.
Roll out the dough to a thin round, large enough to line a 24cm loose-bottomed, fluted tart tin, with an overhang. Prick the base, then line the pastry with baking parchment and baking beans. Bake ‘blind’ for about 20 minutes, then remove the beans and parchment and return to the oven for a further 5 minutes, or until the base is dry and lightly coloured. Remove from the oven and trim the overhang. Set aside.
To make the filling, blanch the nettle tops in boiling water for 2 minutes. Remove and refresh in a large bowl of iced water, then drain the leaves and squeeze out the excess water. Roughly chop and set aside.
Melt the butter in a pan over a medium heat, add the onion, season with a touch of salt and pepper, and fry gently for 8 –10 minutes, or until the onion is soft and lightly coloured. Stir in the chopped nettles and Season with salt and pepper and nutmeg.
Spoon the nettle filling into the tart case – try to avoid pressing it down too much, or the eggs and cream won’t find their way in. Dot the goats cheese randomly over the top. In a bowl, combine the egg, egg yolks and cream to form a custard and season to taste. Pour the custard over the nettles, using a fork to tease the nettle filling into the custard and mingle it all up a bit.
Place the tart in the oven and bake for 30 minutes, until the custard is just set and slightly raised. Allow to cool a little before serving. It’s much better that way.
