Preheat the oven to 180°C.
Peel the orange and then thinly slice the zest. Twice blanch the zest in boiling water - bring the water to the boil, add the zests to the pan boil for 2 minutes. Drain and then repeat a second time. Set aside.
Place the pistachios in a blender with the ground almonds and blitz until fine.
Melt the butter in a saucepan over a low heat until it is a nut brown colour then remove from the heat and allow to cool.
Place the water and the sugar in a saucepan and heat to make a sugar syrup. Add the orange zest to the pan and cook over a low heat for one hour to make the confit orange zest.
Place the ground nuts in a bowl with the flour, icing sugar and the egg whites and mix with a whisk.
Add the butter to this mixture and then chill in the fridge.
Pour this financier mixture in silicone financier moulds and top each financier with a piece of confit orange zest. Cook in the oven for 10-12 minutes.
Remove the financiers from the moulds whilst still warm and serve when cool.
«This mixture can be prepared in advance and then simply baked at the last minute.»