Cornmeal is coarse (like sand) and cornflour is a fine powder. For the best result, I recommend using fine-ground cornmeal in this recipe. Both products should not be confused with cornstarch which is a white, chalky powder. Cornstarch is made from the endosperm of the corn kernel. The starches inside the endosperm are removed, rinsed, dried, and milled into a fine powder. Do not use Cornstarch in this recipe.