Blend the flour and butter in a food processor until they resemble fine breadcrumbs. Add the icing sugar, egg yolks and 1tsp cold water and blend until it forms a dough. Tip onto a floured surface and shape into a ball. Wrap and chill for 1 hour.
Preheat the oven to 190°C, 170°C fan, Gas Mark 5. Thinly roll out the pastry on a floured surface and line a 23cm (9in) loose-base deep tart tin. Line with nonstick baking paper and fill with baking beans. Bake blind for 20 minutes. Lift out the beans and paper and place the tart tin on a baking tray. Increase the temperature to 200°C/180°C fan/Gas Mark 6.
Beat the eggs, sugar, lemon rind and juice and cream in a bowl and leave for 10 minutes. Whisk often to ensure the sugar dissolves. Pour into the pastry case and bake for 20 minutes until lightly set. Leave to cool.
Put the blueberries in a small saucepan with the sugar and 3tbsp water. Cover and heat gently for 3-5 minutes until the blueberries have softened. Blend in a food processor until smooth. Strain through a sieve, pressing the pulp through with the back of a spoon.
Drizzle over the tart and serve with lightly whipped cream.
Make double the pastry cases and freeze. Fill and cook from frozen without first blind baking.