• 150g unsalted butter, at room temperature
• 65g caster sugar, plus more for sprinkling
• ½ teaspoon freshly ground cardamom
• 150g plain flour
• 40g rice flour
• ⅛ teaspoon salt
• 20cm round baking tin

Place the butter into a mixing bowl with the sugar and cardamom and cream together for three to four minutes until pale and fluffy. Tip in the flour, rice flour and salt and mix with a wooden spoon until it comes together into a dough. You may need to use your hand to complete forming the dough but make sure you do this quickly so as not to make the dough greasy from your body heat.

Press the dough evenly into the baking tin with the back of a spoon. There’s no need to grease the pan as the mixture is already very buttery. Go around the edges of the dough pinching gently with your thumb and forefinger, creating a decorative rim. Score into 12 portions as you would slice a cake, then put in the fridge and chill for 20 minutes. Preheat your oven to 160°C (140°C fan).

Sprinkle generously with some caster sugar and bake for 45 to 55 minutes, or until golden all over but not browned. Cool completely in the tin, then turn out onto a wooden board to slice. The shortbread round should come out from the tin easily but if not, go very gently around the edges with a thin knife, place one palm on the front and flip it out. Slice into the 12 scored portions with a sharp knife to serve. The shortbread keeps well for a few days in an airtight container.