Preheat oven to 190°C (170°C for fan assisted), Gas Mark 5.
Line a 25cm loose bottom pie/flan dish with the sweet shortcrust pastry rolled out to approx 5mm thick. Line with paper and baking beans and blind bake for 20 mins, removing the paper and beans for the final 8-10 minutes of the cooking time. Remove from the oven, reduce oven temperature to 160⁰C (140⁰C fan assisted oven), Gas Mark 3.
In the meantime, cut the rhubarb into 2cm pieces, place in a pan and cover with the Cornish Pear Cider. Poach gently until the rhubarb is just soft and NOT breaking down. Drain the fruit and save the poaching juices. For the custard, heat the single and clotted cream with the saffron flecks and beans scraped from the vanilla pod until just before the boil. Beat the egg yolks with the sugar until thoroughly combined. Allow the creams to stand for a minute then add slowly to the egg mixture, beating thoroughly. Return to the pan and stir over low heat for 2-3 minutes until it feels “silky”.
Place the pastry case onto a baking sheet. Pour the custard mix into the pastry case. Stud the custard with the pieces of poached rhubarb, pressing in gently. Place carefully on the middle shelf of the oven for 30 mins or until just set.
While the custard pie is cooking, put the poaching juices back into a pan on a gentle heat and reduce down to a syrup. Add sugar to taste if necessary, but should have a slight sharpness to it.
When the custard is just set, remove from oven and turn oven up to 200°C (180°C fan assisted oven), Gas Mark 5.
Take the sheets of filo, and one at a time loosely crumple up and place on top of the custard and rhubarb filling until it is covered, (should look like crumpled paper-not too flat). Place back into the hot oven and bake for a further 8-10 mins. or until the filo is crisp and lightly golden. Dust with icing sugar. Remove from the flan tin before serving.
Serve a wedge of the pie warm with a dollop of Cornish clotted cream and drizzled with the pink rhubarb syrup. Enjoy.