Defrost the cod - this will take an hour or two. Then slice into fingers.
Preheat the oven to 200C (180C fan / 400F). Mix a pinch of pepper, salt and chilli powder into the cornmeal. Dip a fish piece into the cornmeal to lightly cover. Shake off the excess, then dip into the egg, then into the breadcrumbs.
Repeat with every piece of fish, placing them on an oiled baking try as you go.
Bake for 12-14 minutes until just golden. You can break one open to make sure the fish is cooked through.