This refreshing summer dessert is milky, subtle and slightly tangy. Use the plumpest, most perfectly-ripe strawberries you can find for the best flavor Heat the milk and cream in a heavy-bottomed saucepan until it just reaches a boil. Take off the heat and add the vanilla. In a bowl, whisk the egg yolks and caster sugar together for 1-2 mins until pale and creamy. Slowly add the warm milk to this, whisking all the time. Put a large bowl in your sink (or into another larger bowl), and put water and ice cubes around it. Wash out the saucepan, then pour the cream and egg mixture into it. Set over a low heat and cook, stirring almost constantly, until it thickens enough to coat the back of a spoon, about 10-12 mins (be sure not to let the custard boil or it will curdle). As soon as it’s thick enough, pour it into the bowl set in iced water. Keep stirring the mixture for a couple of mins, then stir at intervals until cooled. Cover and put in the fridge. Chop the strawberries and put them in a food processor with 3 tbsp icing sugar and the balsamic vinegar. Whizz to a purée. Taste for sweetness – you might need more sugar, you might not, depending on your strawberries. Push the purée through a fine sieve over a small bowl to get rid of the seeds. When the ice cream custard has chilled, stir in the strawberry purée and taste – you will probably want a little lemon juice (I find it heightens the flavor). Churn in an ice cream machine following manufacturer’s instructions. It will still be quite soft. Put in a container, cover with cling film or baking parchment and put it in the freezer. This ice cream takes a good 12 hrs. to freeze well. If you don’t have an ice cream machine, pour the mixture into a container and put it in the freezer. Take it out of the freezer every couple of hours and beat it vigorously to break up the ice crystals. You want to end up with a smooth, creamy mixture.
Take the ice cream out of the freezer about 15 mins before serving.