Begin by creaming together the room-temperature butter and caster sugar in a large mixing bowl. Use a hand mixer or wooden spoon to combine them until the mixture is light and fluffy, about 2-3 minutes.

Sift plain flour and cornflour directly into your butter mixture. Use a spatula or wooden spoon to gently fold the flours until just incorporated.

Add the fresh orange zest and chocolate chips to the dough, mixing them through gently with your spatula.

Lightly dust your countertop with flour and pour your dough onto it. Gather the mixture and roll it into a log about 4 cm in diameter, then wrap it in cling film.

Place the wrapped dough in the refrigerator for at least 30 minutes.

Preheat your oven to 150°C (300°F, gas mark 2) and line a baking sheet with parchment paper. Unwrap the chilled dough and slice it into 1 cm thick rounds.

Carefully transfer the baking sheet to your preheated oven. Bake the biscuits for approximately 20 minutes, or until the edges are just golden.

Once baked, remove the shortbread from the oven and let it cool on the tray for about 5 minutes before transferring them to a cooling rack.