This dish has a bit of form. It started as my sister-in-law, Dilou’s lemon tart, which, as far as I am concerned is the pinnacle of the lemon tart universe. Far superior to those heavy-gravity, lemon-flavoured custards. To me there is a philosophical contradiction between the clean austerity of the lemon and the gross richness of the custard base. I prefer the piercing intensity of Dilous thin butter, egg and lemon filling. But I know that I am in the minority here.
To move on, I always welcome blood oranges, or blush oranges as they tend to get called in these deeply sensitive days. They come right at the end of the orange season. Their colour is a delight and their flavour huskily different from the oranges that precede them. Their arrival coincides with that of rhubarb, and as rhubarb and orange is a well tried combo, I came up with this tart, which seemed to go down pretty well.
Incidentally, you may do this already, but grating chilled butter into the flour is the single greatest innovation in my pastry making career. Another thing I owe to my brilliant sister-in-law. It makes distributing the butter quicker and easier, and speed is of the essence when making mastry. Use a coarse grater.
For a 24 cm tart
70g chilled butter
50g icing sugar
6 tbsp (approx) cold water
Sift the icing sugar and flour together into a bowl. Grate the chilled butter into the flour/icing sugar. Mix rapidly with finger tips until you have a granular texture. Add water tablespoon by table spoon until you have a fine, firm dough, Wrap in cling film and chill for at least an hour.
For the filling
2 tbsp caster sugar
2 whole eggs
juice of 1 ½ blood oranges
juice and grated peel of 1 lemon
4 good sticks of rhubarb
Whizz the eggs and sugar together until frothy. Melt the butter. Add the juices and grated peel to the eggs and sugar. Whizz and while whizzing, pour in the melted butter.
Turn on oven to 180C/350F/Gas 4. Roll out the pastry and line the 25 cm tart tin. Cover with baking parchment or greaseproof paper, weight with baking beads, or, in my case, chickpeas, and bake for 15 minutes to set the pastry. Remove the baking parchment/greaseproof paper and the beads/chickpeas. Pour in the blood orange/egg/butter/sugar mix. Cut rhubarb sticks into short lengths and arrange decoratively on top. Bake for a further 30-40 minutes. Dust with more icing sugar before serving.
[NB. The pic at the top is of the tart before cooking.]