Heat oven to 200C/180C fan/gas 6.
Roll the pastry out to about 1cm thick,
then grate over a dusting of nutmeg
using a fine grater. Fold the dough in half,
then roll out again, to the thickness of
2 x £1 coins and large enough to line a
20cm loose-bottomed sandwich tin with
some overhang. Press the pastry into the
tin (leaving the excess draped over the
sides), put onto a baking sheet and chill
for 10 mins. Line the pastry with baking
parchment and fill with baking beans.
Bake for 20 mins, then remove beans
and paper. Bake for another 15 mins until
golden and sandy all over. Trim the edges
of the tart with a sharp serrated knife.
Turn oven down to 150C/130C fan/
gas 2. Whisk together the eggs and sugar
in a large bowl. Put the cream, milk,
vanilla pod and seeds into a saucepan
and bring to the boil. Pour onto the eggs,
whisking as you go. Sieve into a jug. Put
the baking sheet onto the pulled-out
oven rack, then pour in the custard, right
to the top. You may not need every last
drop. Grate over a nice layer of nutmeg,
then slide gently back into the oven and
bake for 1 hr. When it’s ready, the tart
should be set and pale golden on the top,
and have just the merest tremor in the
centre when you jiggle the tray. Cool
completely, then serve in slices.