To make the pastry, rub the butter into
the flour with the lemon zest and a pinch
of salt until it resembles breadcrumbs.
Add the sugar, egg and milk and bring
together to form a dough. This can be
made 2 days in advance.
On a lightly floured surface, roll the
pastry out and use it to line a 20cm tart
tin, leave 2cm of pastry hanging over the
edge. Chill for 30 mins.
Heat oven to 180C/160C fan/gas 4.
Line the case with baking beans, bake
blind for 20 mins, then remove the
beans and continue to cook for a further
20 mins until the base is biscuity. Remove
from oven and reduce the temperature
to 140C/120C fan/gas 1.
Bring the cream, milk, vanilla pod,
lemon zest and a small grating of nutmeg
to the boil. Beat the egg yolks with the
sugar until pale, then pour the hot milk
and cream over, beating as you go. Strain
custard into a jug, allow to settle for a
few mins, then skim off any froth.
Carefully pour the custard into the tart
case, grate some more nutmeg over the
top and bake for 40 mins or until just set
with the very slightest wobble in the
middle. Remove from the oven, trim the
pastry edges off (away from the filling),
then leave to cool completely before
serving in slices with a grating more
of nutmeg, if you like.