Mix the flour, semolina, baking powder and salt in a bowl. Add the buttermilk and all the other ingredients up to and including the sweetcorn, mix with a risotto spoon. Transfer the dough to the prepared tin, smooth down.
Approx. 50 mins. in the centre of an oven preheated to 180°C. Remove from the oven, remove the bread from the tin and place on a rack to cool.