Seville orange, olive oil and pistachio cake

1. Put the whole oranges in a bowl of hand-hot water and scrub gently to remove any wax from the surface. Transfer to a small saucepan and cover with water. Add a lid and bring to the boil. Turn the heat down to a simmer and cook for 1 hours, until the oranges are very soft. Check every now and then, topping up the water if needed. Drain and allow to cool for a few minutes. Meanwhile, pulse the pistachios in a food processor, until they form a rubbly powder; set aside.

2. Preheat the oven to 180˚C, gas mark 4. Grease a 23cm springform cake tin and line the base with baking parchment. Halve the oranges and remove any pips. Whizz to a purée in the small bowl of a food processor. Whisk the egg yolks, olive oil and sugar together in a bowl for a few minutes until thick and pale. Fold in the pistachios, then the orange purée. Whisk the egg whites and salt in a second, clean bowl until stiff. Gently fold into the pistachio mixture, little by little. Spoon into the tin and bake for 45-55 minutes, or until golden and firm on top. Leave to cool in the tin.

3. For the syrup, squeeze the oranges into a pan with the honey. Remove any pips and set over a medium heat; bring to the boil. Simmer for 2-3 minutes. Pierce the cake all over with a skewer, then pour over the syrup, a little at a time, until absorbed; serve.