Preheat the oven to 190°C, fan 170°C, gas 5. Line a 1.5-litre loaf tin with baking parchment.
In a bowl, whisk together the oil, yogurt and eggs. In a separate bowl, combine the flour, oat bran, baking powder and salt, and mix well.
Add the oil mixture, parmesan and courgettes to the dry ingredients and stir until just combined – the mixture will be quite stiff at this stage.
Spoon the batter into the prepared tin and bake for 30 minutes. Turn the tin around and continue to bake for a further 30-40 minutes or until a skewer inserted into the centre comes out clean.
Cool briefly before removing the loaf from the tin to cool completely. Slice and serve with butter, if you like.
Cook's tip: spice up this easy bread recipe with a teaspoon of red chilli flakes.