1 egg, at room temperature
1/2 cup light olive oil
1 cup brown sugar
1 cup plain flour
1/2 cup self-raising flour
3/4 cup pistachio kernels, chopped
7 oz good-quality white chocolate, finely chopped
2 oz good-quality white chocolate, melted
Preheat oven to 350 F. Line 2 baking trays with baking paper.
Using an electric mixer, beat egg, oil and sugar in a bowl until thick and pale. Sift flours over oil mixture. Add pistachio and chopped chocolate. Mix until well combined.
Using 2 teaspoons mixture at a time, roll mixture into balls. Place on baking trays. Using a fork, press dough to flatten slightly. Bake for 12 to 15 minutes, swapping trays after 8 minutes, or until biscuits are light golden. Stand for 5 minutes on trays before transferring to a wire rack to cool completely.
Drizzle biscuits with melted white chocolate. Allow to set. Serve.