If you have a stand mixer with a dough hook, add all ingredients (except the cornmeal) to the bowl and mix for around 7 - 10 minutes until the dough is smooth and elastic. My Kitchen Aid Pro
suggests using setting 2 for dough. Once it forms a ball, give it a poke and check it's not too sticky. If it is add a tablespoon of flour at time, giving it a chance to mix in between additions, until it is just very slightly tacky to touch.