Heat a cast-iron skillet on medium-high heat.
While the skillet is warming up, mix the grated parmesan cheese and Italian seasoning in a shallow dish.
Once the skillet is hot, pour in just enough olive oil to cover the whole bottom of the skillet.
Take one fillet at a time and press both sides into the cheese and seasoning mixture, making sure the entire piece of fish is covered.
Carefully put the "breaded" fish into the skillet and let it cook for 2-3 minutes.
Flip to the other side for another 2-3 minutes or until the fish is thoroughly cooked.