Cut the fish into 6 pieces. Boil the garlic for 2 minutes. Cut the garlic in small pieces. With a knife, make 3 to 4 incision in the fish and insert a piece of garlic in each incision. Keep aside.
Slice the onion and the fennel. In a large saucepan, melt the butter on medium heat, add the onion and cook them 5 to 6 minutes, add the fennel, and sweat 5 more minutes. Add the wine and cream and cook 10 minutes, add salt and pepper, Keep aside.
In a nonstick pan, heat olive oil and sear the fish, add butter, salt, and pepper, keep cooking 6 to 7 minutes, and ”feed” with the cooking oil and butter. Let the fish rest for 5 minutes and serve.
You can enjoy this dish on its own or with some white rice.