1. Preheat the oven to 200˚C/180˚C fan/gas mark 6.
2. In a bowl, mix together the flours, wheat bran, brown sugar, bicarbonate of soda and salt. Mix to combine together well.
3. In a jug, mix together the oil, egg and buttermilk.
4. Make a well in the centre of the flour mixture and pour in the wet ingredients. Stir until just combined, but do not over-mix — once mixed, leave it alone!
5. Pour the mixture into a well-greased loaf tin and bake for one hour until it is golden and baked through.

Note: olive oil can be used as an alternative to sunflower oil, if you wish.