Preheat the oven to 150˚C.
Grease and line with parchment paper an 8inch bread tin.
Place the flours, porridge oat, salt into a large mixing bowl. Sieve in bread soda and combine with the flour mixture.
Make a well and add the egg and treacle. Slowly pour in the buttermilk and stir to combine to get a soft sloppy mixture, not too dry.
Place into a the tin.
Brush the top of the bread with a leftover mixture of buttermilk and sprinkle of porridge oats over.
Bake in the oven for 50 minutes Remove from the tin and place back in the oven for 10 minutes to allow the bread to cook and dry uniformly in the oven or until hollow when tapped on the base.
Remove from the oven and allow the bread to cool down.
This loaf will keep fresh for 3-4 days and is suitable for freezing.