In a bowl mix together both flours. Then add in the salt and bicarbonate of soda, and mix again thoroughly. You don’t want any pockets of salt or bicarbonate of soda, in the bread.   Add in the buttermilk and stir with a wooden spoon, until the dough starts to come together. 

Tip the mixture out onto a floured surface and gently bring the mixture together.  Unlike many other bread recipes, you do not need to knead this one but just bring it together into a ball shape. 

Gently flatten the top with the palm of your hand and then cut a cross into the top (make sure you do not cut all the way through) so it shows defined quarters.  Dust the top of the dough with more of the flour (you can use the plain or wholemeal flour for this) and then set aside for 30 minutes, whilst you pre-heat your oven to 200 degrees centigrade. Once 30 minutes has passed, bake for around 30 minutes. 

You can check it is cooked by tapping the base, which should sound hollow.

Place on a wire rack to cool properly. It will last for around a day or two, but always best eaten on the day of baking.