Pre-heat the oven to 170°C.
Grease 12 x individual non-stick loaf tins. In a large mixing bowl, combine the sifted flour, baking powder, bicarbonate of soda and salt. In another mixing bowl, whisk together the egg, Parmesan and vegetable oil until smooth, then fold in the grated courgette and lime zest. Add this mixture to the flour mixture and fold together until just combined.
Spoon into the prepared loaf tins and bake for 20-25 minutes until a cake tester comes out clean from their centres. Remove from the oven and allow to cool for 5 minutes in the tins before turning out onto a wire rack to finish cooling.
Serve warm or cold garnish with a sprig of basil.