Step 1

Preheat oven to 220°C/430°F (200°C fan).

Step 2

Line tray with baking paper.

Step 3

Whisk both flours (not Extra Flour), baking soda and salt in a bowl.

Step 4

Add buttermilk, stir until it's too hard to stir anymore.

Step 5

Sprinkle 2 tbsp Extra Flour onto work surface, scrape out dough, sprinkle with more flour.

Step 6

Gently knead no more than 8 times, bring together into a ball. (Note 4)

Step 7

Transfer to tray, pat into 2.5cm/1" thick disc.

Step 8

Cut cross on surface 1cm / 0.3" deep using serrated knife.

Step 9

Bake 20 minutes. Turn oven down to 200°C/390°F (180°C fan).

Step 10

Bake further 20 minutes, or until the base sounds hollow when tapped in the middle.

Step 11

Transfer to rack and cool for at least 30 minutes before slicing.