Mashed plantains make for a tasty Cuban-inspired side dish.
Preheat oven to 375 degrees. Sprinkle plantains with salt and cayenne; drizzle with oil to coat. Arrange, cut sides down, on a rimmed baking sheet. Roast until cut sides of plantains begin to caramelize, about 20 minutes. Turn plantains; roast 10 minutes more.
Mash hot plantains on baking sheet with a potato masher until somewhat smooth (some large chunks should remain). Transfer to a serving bowl, and drizzle with lime juice.
Soft, with peels that are mostly brown or black, plantains (platanos maduros, in Spanish) are available in Latin-American markets and many grocery stores.