Preheat An Outdoor Grill For Medium Heat, And Lightly Oil The Grate. Whisk The Extra-Virgin Olive Oil, Minced Garlic, Black Pepper, Cayenne Pepper, Salt, Lime Juice, And Grated Lime Zest Together In A Bowl To Make The Marinade. Place The Mahi Mahi Fillets In The Marinade And Turn To Coat; Allow To Marinate At Least 15 Minutes. Cook On The Preheated Grill Until The Fish Flakes Easily With A Fork And Is Lightly Browned, 3 To 4 Minutes Per Side. Garnish With The Twists Of Lime Zest To Serve.