Lightly grease a 23cm / 9in loose-based fluted tart tin. Sift the flour with the salt into a
food processor, add the butter and process until the mixture resembles fine breadcrumbs. Tip the
mixture into a large bowl and add a little cold water, just enough to bring the dough together.
Turn out onto a lightly floured work surface. Roll out to 8cm / 3 1/4 in larger than the tin. Line
the tin with the dough and trim the edge. Line the tart shell with baking paper and fill with dried
beans. Chill in the refrigerator for 30 minutes.
Remove the tart shell from the refrigerator and bake in a preheated oven, 190ºC / 375ºF / Gas
Mark 5, for 10 minutes. Remove the paper and beans and bake the tart shell for 5 minutes more.
Remove from the oven and reduce the oven temperature to 325ºF / 160ºC / Gas Mark 3.
Arrange the crab meat and watercress in the tart shell, reserving a few watercress leaves for
garnishing. Whisk the milk, eggs and egg yolks together in a bowl. Bring the cream to simmering
point in a saucepan and pour over the egg mixture, whisking all the time. Season with salt and
pepper and stir in the nutmeg and chives. Carefully pour over the crab and watercress and sprinkle
over the cheese. Bake for 35-40 minutes until golden and set. Let the tart rest for 10 minutes
before serving, garnished with the reserved watercress.