Using an electric mixer whisk up the egg yolks with the caster sugar until pale and thick. Add the cornflour and mix it in, then pour the warm milk in with the mixer still going

Pour the mixture back into the pan and heat it at a medium-high heat whilst continously stirring. When it starts to thicken, whisk it to keep it smooth and stop any lumps

Sieve it required to remove any lumps, then put it in a bowl and covered it with cling film. Make sure the cling film is touching the creme patisserie so that a skin doesn't form on it. Leave it in the fridge overnight to cool

To make the pastry rub the butter into the plain flour until it resembles breadcrumbs

Add the eggs and mix to form a dough. Wrap it in cling film and chill it in the fridge for 30 minutes

Roll out the pastry and line a 23cm tart tin. Prick it all over with a fork

Line the pastry with baking paper then pour in baking beans (or dry rice if you don't have them) bake it on 180C/106C Fan/350F/Gas Mark 4 for 15 minutes

Remove the baking beans and baked it again for 10-15 minutes until the bottom is fully cooked and it is golden brown all over

When the tart case is fully cool fill it with the creme patisserie and smooth it out

Slice up the nectarines and arranged them in circles on top, then place the billberries in the gaps

To glaze the tart, warm up the apricot jam in a pan. Sieve it to remove any lumps, and use a pastry brush to generously brush it all over the tart