Mix all the dry ingredients incl the parmesan but keeping the onions apart and mix well.
Make a well in the middle and add the buttermilk. Mix and knead briefly by hand. You want it to come together but no need to keep kneading longer.
Turn out onto a baking tray lined with baking paper and form a round bread of around 2,5 cm high.
Place in the oven for 20 minutes. After 20 minutes, turn the heat down to 200˚C and spread the onions and the extra cheese over the top. Continue to bake for another 10 minutes. Make sure it is not becoming too brown so keep an eye on the bread.