Make the curd the night before. Heat
the milk in a large pan. As it comes to a
gentle simmer, add the lemon juice. Turn
the heat to low and gently stir while the
curds form. Do not stir too quickly or you
will break up the curds. Once the mixture
resembles watery liquid with creamy
lumps in it, remove the pan from the heat
and allow the curds to cool in the whey.
Drain the curds overnight through a clean
tea towel and save the whey for making
scones, as you would buttermilk.
To make the pastry, blend the flour,
baking powder, butter, sugar and a pinch
of salt in a food processor until the butter
is almost all combined – leave a few small
lumps of butter to lighten the dough. Tip
the dry mix onto a work surface and make
a well in the centre. Add a little cold water
to make a smooth, but not sticky dough.
As soon as the mixture comes together,
knead very lightly, wrap in cling film and
chill for at least 20 mins. Can be made up
to 2 days ahead and chilled.
To finish the filling, beat the butter and
sugar until soft, then add the egg, a little
bit at a time. Add the curds to the mixture
and lightly whisk to break up any large
lumps. Once blended, add the currants.
Heat oven to 180C/160C fan/gas 4. Roll
out the pastry to line a greased 20cm
shallow pie dish or tart tin. Spread over
the curd mix and bake for 35-40 mins
until browned and the pastry is cooked.
Leave to cool, then cut into slices and
serve on its own or with a drizzle of cream.