How to Make It
Preheat the oven to 400°. Set the chicken in a roasting pan, rub with 1 tablespoon of the oil and season with salt and pepper. Roast for about 1 1/2 hours, basting often, until golden and cooked through. Transfer to a platter. Discard any fat from the pan and set it over 2 burners. Add 1/2 cup of water and simmer over moderate heat for 2 minutes, scraping up the browned bits. Pour the juices into a bowl. Cut the chicken into 1-inch pieces. Discard the skin and bones.
Heat 1 tablespoon of the oil in a large skillet. Add the onion and bell pepper and cook over moderately low heat, stirring, until softened, about 8 minutes. Add the garlic and scallions and cook, stirring, until fragrant, about 3 minutes. Add the tomatoes and simmer over moderate heat until the liquid evaporates, about 5 minutes. Stir in the thyme and chile powder and cook, stirring, for 3 minutes. Add the chicken and juices and simmer for 2 minutes. Season with salt and pepper and transfer to a bowl.
Preheat the oven to 400°. Wipe out the skillet and heat the remaining 1 cup oil over moderately high heat until shimmering. Add a single layer of plantain slices and fry, turning once, until well browned, about 4 minutes per side; if necessary, lower the heat to cook the plantains all the way through. Transfer to a plate to cool and repeat with the remaining plantains. Lightly flatten the slices with a rolling pin or meat pounder to 1/3-inch thickness between 2 pieces of sturdy plastic wrap. Press the flattened plantains into a 9-inch glass pie plate, overlapping them slightly to cover the bottom.
Spoon the stew into the plantain-lined pie plate. Sprinkle with the feta and bake for about 45 minutes, or until heated through and the plantains on the bottom sizzle. Cut into wedges and serve.