Mix the cornmeal, flour and a good pinch of sea salt in a large bowl. Stir the yeast into 275ml of warm water, then add to the bowl and mix to form a pliable sticky dough, adding a splash more water, if needed.
On a clean flour-dusted surface, divide into 6 balls, then flatten each into a 10cm round, pushing your fingers into the top to give you a ripple effect. Place on a lightly oiled tray, cover with a clean damp tea towel and leave to prove for 45 minutes.
Working in batches, drizzle a little oil into a large non-stick frying pan on a medium heat. Once hot, cook a few dough rounds for 2 to 3 minutes on each side, or until golden and perfectly charred, then repeat, topping up the oil between batches, if needed.