Dice tomatoes, finely chop parsley and garlic. Knead together with breadcrumbs, parmesan and butter. Season with salt and pepper.
Brush a baking dish with oil and let it heat up in the preheated oven at 200 ° C top / bottom heat on the 2nd rail from the bottom.
Drizzle the fish fillets with lemon juice, season with salt and pepper. Spread the crumb mixture on the fillets and press down. Place the fish in a hot casserole dish and cook for 15 minutes on the 2nd rack from the bottom.