To prepare the caramel
Bring the sugar and water to the boil in a wide-bottomed pan without stirring. Reduce the heat and simmer, swirling the pan occasionally until the sugar darkens to a hazelnut-brown caramel. Pour in the milk, dissolve the caramel.
To make the custard
Beat the milk with all the other ingredients up to and including the egg, pour into the caramel while continuing to whisk, bring to the boil over a medium heat, whisking continuously. Remove the pan from the heat, whisk for a further 2 mins., returning the pan to the hob a few times until the mixture thickens and turns creamy. Pour the custard into a bowl through a sieve, place a sheet of cling film over the custard to prevent a skin from forming Leave the custard to cool, then refrigerate for approx. 2 hrs.
Carefully fold the whipped cream into the custard. Place the strawberries in a bowl, mix with the sugar and lemon juice, scatter on top.