Add the oatmeal, the ground flaxseeds, and the water into a bowl, mix to combine. Let it sit for 10 minutes.
On medium-low heat, add the cabbage and the onions to a nonstick skillet, (or add a few drops of oil or water to the skillet) stir fry until soft, adding a little bit of water every time you notice that the cabbage and onions are getting dry. Sauté for 10 minutes or until the cabbage and onions are very soft and the water is completely dried out.
Add the ground cornflakes to a plate.
Let the cooked cabbage and onions cool down completely, then add it into a large bowl along with the remainder of the ingredients except for the ground cornflakes. Mix everything until well incorporated, let it sit for another 5 minutes.
Take a small piece of the form a small ball by rolling the dough in your hands, then flatten it up into a disc directly in the cornflakes plate, cover the schnitzel with the cornmeal on both sides and immediately add it to your nonstick skillet, let it fry for 3 minutes each side on medium heat. If you prefer to use an oven you can bake it for 20 minutes at 180℃ (356℉) or for 10 - 15 minutes in the air fryer at 180 -185℃.