1. Pre-heat the oven at 392ºF. Put it in broil setting..
2. Mix the parmesan cheese with the butter, until you get a soft paste. Season with the dry basil, black pepper and a pinch of salt. Set aside.
3. Season the fish fillets with salt and pepper.
4. Grill them 5 inches away of the fire for 2 or 3 minutes.
5. Grill the other side of the fillets for 2 more minutes.
6. Take the fillets out of the oven and cover them with the parmesan cheese sauce, plus the grated lemon zest.
7. Turn the heat down to 194ºF. Now put the fillets back in the oven with the sauce, and cook for 2 more minutes, or until the cheese cover has brown and the fish has soften.