FOR THE PASTRY
100g/4oz caster sugar
250g/9oz plain flour, plus extra for dusting
25g/1oz ground almonds
1 egg, beaten
FOR THE FILLING
200g/8oz caster sugar
juice and finely grated zest 4 orange
juice 1 lemon
142ml pot double cream
140g/5oz dark chocolate, chopped
FOR THE CARAMELIZED ORANGE SALAD
2 oranges, peeled and zest finely shredded
200g/8oz caster sugar
Make the pastry by tipping the butter, sugar, flour and almonds into a food processor, then whizzing until they resemble breadcrumbs. add a little egg at a time, pulsing until the pastry comes together – you may not need all the egg. tip out the pastry and knead briefly to bring together. Shape into a flat round, wrap in cling film and chill for 30 mins.
Heat oven to 200C/fan 180C/gas 6. On a floured surface, roll out the pastry to line a 23cm loose-bottomed tart tin, leaving an overhang around the edges. Line the case with baking paper, fill with baking beans, then blind-bake for 20 mins until golden. Remove the beans, then continue to cook for 10 mins until the base is also golden, then set aside to cool. Reduce oven to 150C/fan 130C/gas 2.
Meanwhile, make the filling. Whisk the eggs and sugar well, then whisk in the juices, zest and cream. Scrape into a jug and set aside. Melt the chocolate in a bowl over a pan of simmering water or in the microwave. Once the case is cool, trim the overhanging pastry, then brush liberally with chocolate. Chill briefly to set, then repeat and set again.
Return the tart case to the oven, then quickly yet carefully pour in the orange custard to the top. Bake for 45-50 mins until the custard has just set, then cool in the tin. If you’re making ahead, this can now be chilled overnight.
For the orange salad, segment the oranges over a bowl, catching any juice and squeezing out the leftover membrane. Put the zest in a pan of cold water, bring to the boil, then strain and set aside. Melt the sugar in a saucepan with a splash of water, then bring to the boil. Bubble until you have an amber caramel; then, still on the heat, tip in the zest, orange segments and juice. Swirl around for a moment before tipping into a bowl. turn the tart out onto a plate and drizzle a little syrup from the oranges over. Spoon a segment or two of orange, a bit of zest and a little syrup on each portion of tart and serve the rest of the oranges separately.