Start grilling the plantain with the flesh side down. Grill for 5-7 minutes until grill marks form and the plantain slightly softens. Turn over to peel side and grill for about 1-3 minutes. You know it’s done when the plantain begins to pull away from the peel. Sprinkle with sea salt if desired. These can be served with a savory dish when topped with salt or become a sweet dish with cinnamon, honey, whipped cream, or ice cream.