Preheat the oven to 400˚F. In a small saucepan, mix together the butter, parsley, garlic, salt, pepper, lemon juice and lemon peel. Set aside.
Pat the mahi mahi fillets dry with paper towels.
On large cast iron skillet, heat the olive oil over medium high heat. Once the oil is hot, add the fish fillet and top with salt and pepper to taste. Cook until browned, around 3 minutes. Flip and turn the heat off.
Place the skillet in the preheated oven for 5 minutes, or until the centre is cooked through.
Meanwhile, heat the small saucepan with the garlic mixture on medium heat, stirring until melted. Pour on the fish.
Notes
Make sure whatever skillet you are using to cook the mahi mahi is oven proof. Cast iron skillets work the best here.
This is best enjoyed immediately, but can be stored in an airtight container in the fridge.