To cut the onion into slices, peel and cut the onion in half going through the root. Place on a cutting board with the cut half side down. Cut into thin slices vertically going through the entire length of the onion. Put aside.
To make the yeast ferment, place 3 tablespoons of honey in a large bowl. Pour 8 the of water over the honey. Do not stir. Spread the yeast over the water. Let stand at room temperature for about 15 minutes or until bubbles appear. *
Add the remaining two cups of water, 3 tablespoons of olive oil to the yeast mixture. 50 g of corn flour and whole wheat flour; stir until mixture is completely homogeneous.
Add the salt, stirring with 250 g of all-purpose flour. Stir, and of the 'remaining flour, add enough so that the mixture adheres to the sides of the bowl.
* If the yeast does not form bubbles, it means that it is no longer active. Dump the yeast mixture and start over. You should always check the expiration date on the yeast package. On the other hand, putting too much hot water will kill the yeast; it is better to use a thermometer.
Put the dough on a surface dusted with flour. To knead together with the remaining flour, fold the dough in half towards you and then push it out with your forehand. Turn the dough a quarter of a turn, and continue folding, pushing and turning, until the dough is smooth and shiny, about 10 minutes.
Divide dough into two parts. Place each half in a large, lightly greased bowl. Turn over both pieces of dough to spread the surface with butter. Cover both pieces with a clean kitchen towel and leave the dough in a warm place (30-C) to rise until it doubles the original volume. (Insert 2.5 cm of the tips of two fingers into the dough. The dough will be ready if the marks remain.)
Meanwhile, combine onion, vinegar, and remaining half cup of honey in medium bowl. Let it rest for at least 1 hour, at room temperature.
Butter two pizza oven trays (30 cm) and sprinkle with additional cornmeal. Roll out the dough and shape it into the baking sheet; Make finger tips 9. Cover the dough with buttered plastic wrap; let it rise for 1 hour. The dough will increase twice in volume.
Preheat the oven to (200oC).
Squeeze the onions and distribute them on top of the dough. Moisten on top with the remaining 3 tablespoons of olive oil, Parmesan cheese, and onion salt; garnish with pepper.
Cook 25 to 30 minutes until the dough has a crust and is golden brown. Serve hot.
The amounts indicated make 2 loaves (6 to 8 servings each)