Rhubarb & Custard Flan

Method

1. Preheat oven to 180°C. Roll out the pastry, enough to line a deep, 23cm round tart tin (ideally with a removable base). Trim the edges of the pastry sheet, then prick the base with a fork and allow to chill in fridge for 30 mins.
2. Meanwhile, place the rhubarb in a large ovenproof dish. Stir through 120g of caster sugar and the split vanilla pod.
3. Loosely cover with foil and bake for 20-25 mins, or until the rhubarb is just tender. Drain any liquid and set aside to cool.
4. Cover the base of the tart with baking paper and fill with baking beans, or rice. Blind bake the tart for 15 mins, then remove the paper and beans. Bake for a further 5 mins until the tart is cooked but still quite pale. Brush the tart base with the egg white to seal it.
5. Reduce the temperature of the oven to 150°C. In a bowl, combine the remaining sugar with the cornflour and gradually whisk in the eggs and crème fraiche. Carefully scrape out the vanilla seeds from the reserved pod and whisk to combine.
6. Arrange the rhubarb on the tart base before pouring over the custard mixture.
7. Bake in the oven for 30 mins, or until the tart is just set in the middle. Remove from the oven and allow to cool in the tin before serving.