In a deep 10-inch skillet, heat 2 tablespoons of the oil. Add the fennel and season lightly with salt and pepper. Cover and cook over low heat, stirring, until lightly browned and tender, 20 minutes. Add the scallions, cover and cook until they are just tender, 2 minutes. Transfer to a bowl. Add the remaining 1 tablespoon of oil to the skillet and add the curry powder. Cook over low heat, stirring, until fragrant, about 1 minute. Add the wine and boil over high heat until reduced by half, about 1 minute. Add the clam juice and boil until reduced by half, about 3 minutes. Cover and remove the skillet from the heat.