The plantain is a jumbo cousin of the banana. It’s always served cooked, usually as a starch or vegetable. A green plantain tastes bland like a potato. When ripe (the skin will be black), plantains become as sweet as a ripe banana. Both green and ripe plantains can be grilled, but I prefer the ripe ones: The fire caramelizes the sugars in the plantains and makes them candy sweet. Grilling the plantain pieces in their skins keeps them moist and tender.