WHAT YOU NEED

250g plain (all-purpose) flour, plus extra for dusting
100g rice flour
100g caster (superfine) sugar
A pinch of salt
225g chilled unsalted butter, cut into cubes

For the cardamom sugar

6 cardamom pods
110g caster (superfine) sugar

Preheat the oven to 160°C. Grease and line a 30 x 18 cm (12 x 7 inch) cake tin.

Line two baking trays with baking paper.

Place all the ingredients in a food processor and blitz until roughly combined. Turn the mixture out onto a very lightly floured work surface and gently knead to bring it together into a dough.

Press the dough into the tin and place in the fridge to chill for 20 minutes.

For the cardamom sugar, toast the cardamom pods in the oven for 10 minutes or until they are aromatic and a pale olive green.

Place in a spice grinder or food processor and blitz until as fine as possible. Mix in the sugar.

Cut the chilled shortbread into fingers, bars or small squares and place on the baking trays. Using a fork, prick the surface of each biscuit a few times, then generously sprinkle with the cardamom sugar.

Bake the shortbread for 15–20 minutes or until light golden.

Leave to cool on a wire rack, then store in an airtight container for up to 2 weeks.