Slice the peel away from the lemons with a very sharp knife, making sure to remove all the pith.

Place the lemon peel into a saucepan along with the milk and heat until just below boiling point.

Remove the milk from the heat and leave the milk to infuse with the lemon for at least 2 hours (or overnight in the fridge which is what I usually do).

Whisk the egg yolks with the sugar with a balloon whisk in a large mixing bowl until pale and thick then whisk in the cornflour.

Strain the chilled lemon infused milk into a large measuring jug then pour the milk in a very thin and steady stream into the eggs, whisking all the while until all the milk has been incorporated.

Pour the liquid custard mixture into a large saucepan and bring to a very gentle boil and the custard has thickened, stirring all the time.

Remove from the heat, place a piece of baking parchment or cling film on top of the surface of the custard and allow to sit for 10-15 minutes just so it’s not piping hot. Remove the parchment or cling, give the custard a quick whisk to ensure it’s still lovely and smooth and either pour into a serving jug or serve directly from the saucepan.