2 red fish fillets on the half shell

marinade:
1/4 cup- Worcestershire sauce
1/4 cup- extra virgin olive oil
1/4-1/2 teaspoon- cayenne pepper
1/4 teaspoon- dried thyme
1 Tablespoon- paprika
Sea salt and fresh ground black pepper to taste

1 yellow onion
1 lemon
2 whole garlic cloves
1 bunch – parsley
1/2 stick (unsalted/diced)- butter

– Lay red fish fillets in a bowl flesh side up.
– Pour marinade ingredients over the fillets, rub in well, and set aside.
– Thin slice the onion, garlic, and half of a lemon.
– Squeeze the reserved half a lemon over the fish.
– Lay the thin sliced onion and garlic over the fish and allow the fillets to marinade for 30 minutes.
– Preheat your grill to medium heat, and place the fillets on the grill flesh side down, reserving the sliced onions and garlic.
– After the flesh side has nice color and grill marks, turn the fillets flesh side up, and add the reserved onion and garlic slices from earlier.
– Once fish has been cooking for a total of about 20 minutes, place a cast iron sauce pan on the grill.
– Add in butter, once it is half way melted remove the pan from the grill and add parsley.
– Season sauce with sea salt to taste and a squeeze of lemon.
– Remove the red fish from the grill and pour sauce over the top. Garnish the top of the fillets with thin sliced lemon, and enjoy!

source