Elderflower and gooseberry tart

Method

1. If you have fresh elderflowers, strip the flowers off the stalks using the tines of a fork and put them in a jar or lidded container. Add the sugar, stir to combine, then cover and set aside at room temperature for at least 24 hours. This will infuse the sugar with the flavour of fresh elderflower. If you don’t have fresh elderflower to hand, simply skip this step.
2. For the pastry, put the flour and butter in a food processor and pulse to create a breadcrumb-like texture. Add the icing sugar and pulse again, then add the egg yolk with 2 tbsp ice-cold water and continue to pulse, just until it starts to come together as a dough, adding a touch more water if needed. Shape the dough into a disc, then wrap and chill for 30 minutes.
3. Put the gooseberries and elderflower cordial in a pan over a medium-high heat, bring to the boil, then cook for about 4 minutes until the berries have collapsed. Use a stick blender to whizz until smooth. Leave to cool completely.
4. Roll out the pastry on a lightly dusted worktop to 3mm thick, then carefully transfer it to the tart tin and press in the sides and base. Prick the base all over with a fork, then chill for 30 minutes.
5. Heat the oven to 220°C/200°C fan/gas 7 with a baking tray inside to heat up. Run your rolling pin over the top of the tin to remove the excess pastry overhang and create a flush, neat finish. Fill the pastry with a sheet of baking paper and some baking beans or uncooked rice. Slide the tart tin onto the hot baking tray and blind bake the pastry for 15 minutes, then remove the beans/rice and paper and bake for another 10 minutes. Beat the egg white a little to loosen it, then brush it all over the pastry to create a seal and bake for another 2-4 minutes until golden and crisp.
6. Meanwhile, crack the eggs into a large jug, add the sugar (use a fine sieve to remove the elderflower heads if needed) and whisk together for a minute or so until turning paler. Stir in the cooled gooseberry and elderflower mixture and the cream.
7. Turn the oven down to 170°C/150°C fan/gas 3½. Sliding out the oven shelf the tart is on without removing it, carefully pour the gooseberry elderflower filling into the pastry case so it reaches the top edge of the pastry. Gently slide back into the oven so none of the filling spills, then bake for 20-25 minutes until just set with a slight wobble in the centre.
8. Leave to cool in the tin for 15 minutes, then remove from the tin onto a serving plate to cool. You can enjoy the tart while still a little warm or completely cool. Dust with a little icing sugar, then serve with crème fraîche.