Pour milk into a pan. Split vanilla pod
lengthways and scrape out seeds, adding
both to the pan. Slowly bring to the boil.
Reduce heat and simmer for 2 mins.
Meanwhile, put egg yolks, sugar and
flour into a bowl. Using an electric beater,
whisk until pale and fluffy. Whisk in a third
of the hot milk, then add remainder. Add
mixture to the pan and bring to the boil,
stirring, until the custard is thickened.
Reduce heat and simmer for 2 mins,
stirring constantly. Fish out vanilla pod,
beat in the butter and pour into a bowl.
Cover surface with cling film, leave to cool,
then chill. Can be made 1 day ahead.
Heat oven to 160C/140C fan/gas 3. Line
the base and sides of a 23 x 33cm Swiss
roll tin with baking parchment. Blend
cornflour, vinegar and vanilla extract to a
smooth paste. Tip egg whites into a clean
bowl. Mix together sugars in a separate
bowl. Whisk egg whites until stiff, then
gradually whisk in the sugar, alternating
with a little paste until the mixture is
thick and glossy. Spoon into the prepared
tin and smooth the top. Bake for 20 mins
until crisp on top. Meanwhile, whisk the
cream and fold into the custard.
Remove the meringue from the oven
and turn out onto a sheet of baking
parchment, peel off the lining paper and
leave to cool for a few mins.
Spread the custard evenly over the
meringue to within 5cm of the short ends
and to the edge of the long ends. Scatter
with the sliced strawberries. Using the
parchment to help you, roll up the
meringue from one short end. Transfer to
a flat plate and dust with icing sugar