Rhubarb and Custard Tart with Pistachios

Method

1. Make the shortcrust pastry.

2. Sift the flour and salt into a large bowl. Cut the butter into cubes, toss in the flour and then rub in with your fingertips.

3. Keep everything as cool as possible; if the fat is allowed to melt, the finished pastry may be tough. When the mixture looks like coarse breadcrumbs, stop. Add the icing sugar.

4. Whisk the egg or egg yolk and add some water. Using a fork to stir, add just enough liquid to bring the pastry together, then discard the fork and collect it into a ball with your hands, this way you can judge more accurately if you need a few more drops of liquid. Although rather damp pastry is easier to handle and roll out, the resulting crust can be tough and may well shrink out of shape as the water evaporates in the oven. The drier and more difficult-to-handle pastry will give a crisper, shorter crust.

5. Wrap in parchment paper and leave to relax in the fridge for at least 1 hour before using. It will keep for a week in the fridge and also freezes well.

6. Line a tart tin (or tins), with a removable base and chill for 10 minutes. Line with paper and fill with dried beans and bake blind in a moderate oven 180°C/Gas Mark 4 for 15-20 minutes. Remove the paper and beans, paint the tart with a little egg wash and return to the oven for 3 or 4 minutes.

7. Arrange the cut rhubarb evenly or in a chevron pattern on the base of the tart shell. Sprinkle with 1-2 tablespoons caster sugar.

8. Whisk the eggs well, with the 3 tablespoons sugar and vanilla extract, add the cream. Strain this mixture over the rhubarb and cook in the preheated oven for 35 minutes until the custard is set and the rhubarb is fully cooked.

9. Scatter with coarsely chopped pistachios. Serve warm with a bowl of softly whipped cream.