Peach, sesame and yoghurt semi-freddo

Put the peaches in a saucepan with the lemon juice, 25g of the sugar and a splash of water. Cover and stew gently until the peaches are just soft but not mushy. Spoon out a third of the chunks with a slotted spoon to cool, and carry on cooking the rest, covered, until they are mushy. Whizz these to a purée with any syrup in the pan, in a blender or food processor, and cool these completely too.

When the peach purée is cool, put the remaining 250g sugar in a pan with 225ml water and dissolve over a very low heat. Once the sugar has dissolved, increase the heat and boil until the mixture reaches 120C on a sugar thermometer or test it by dropping some mixture into a glass of cold water. If you can roll the lumps into a soft ball that flattens when you press it, it is ready. As the sugar syrup is nearing temperature, put the egg whites into a large bowl and beat them with an electric whisk until stiff peaks form. With the beaters still running in the whites, carefully pour in the hot sugar syrup and beat until thick again.

Put the yoghurt into another large mixing bowl, then fold in the meringue mixture, followed by the peach purée. Swirl through the peach chunks and sesame snaps, and scrape the lot into a container. Freeze until solid, overnight is best, before scooping into waffle cones or bowls.