Preheat oven to 425f.
Line a 13×9-inch baking dish with parchment paper.
Add zucchini slices to the bowl and sprinkle two tablespoons of sea salt over zucchini.
Let sit for at least 15 minutes.
Squeeze the zucchini to catch the juice and reserve ¼ cup of the juice.
Lay the zucchini slices on a paper towel to soak up remaining moisture.
Mix the flour, cornmeal, Parmesan, and oregano in a large bowl.
Add the eggs, olive oil, and zucchini juice. Mix well.
Fold in the zucchini slices.
Spread dough evenly over the base of the baking dish.
Bake on top rack in the oven for 35 to 40 minutes or until golden and crisp.
Allow to cool slightly before cutting into squares.
Serve as is or on a plate with dressed arugula.
