For the rhubarb
1kg cleaned rhubarb, cut into 5cm pieces
150g caster sugar
For the semifreddo
6 large egg yolks
175g caster sugar
100ml double cream
150ml plain, whole milk yoghurt
Seeds scraped from 1 vanilla pod
1. First, cook the rhubarb.
2. Heat the oven to 150C/300F/gas mark 2.
3. Put the rhubarb in a large, wide oven dish with just the water that clings to it after washing, toss with the sugar, cover with foil and bake for 30-60 minutes.
After 10 minutes, turn over gently, so as not to break up the rhubarb,
then check after 25 minutes, and regularly thereafter, poking it with the tip of a sharp knife – you want to catch it at the point when it's perfectly tender but still holding its shape.
4. Transfer three-quarters of the rhubarb and its juice to a dish and refrigerate. (If you're making this more than two days in advance, freeze this compote and defrost in the fridge before serving.)
5. Puree the remaining rhubarb and juice.
6. Line a 1kg loaf tin with clingfilm (make the tin slightly wet first, to help the clingfilm to cling).
7. Put the egg yolks and sugar in a large bowl over a pan of barely simmering water and whisk for five minutes (ideally, use an electric whisk) until thick, pale and creamy. The mix should hold a trail when you lift the beaters – ie, ribbons of the mix should sit on the surface before sinking back in.
8. Fold the puree into the moussey mixture, then transfer to the fridge.
9. When the rhubarb custard mixture is cold, whisk the cream, yoghurt and vanilla seeds until they just hold very soft peaks (if it's too stiff, it will be hard to fold in).
10. Gently fold into the custard with a large metal spoon, keeping in as much air as possible, pour into the prepared tin and freeze until solid.
11. Transfer the semifreddo to the fridge an hour before serving, to soften, then turn out of the tin.
Cut into thick slices and serve with a spoonful of the compote.
My version of easy Vanilla Ice Cream (semifreddo)