Preparation Using a sharp large heavy knife, cut ends off plantains and slit through peel lengthwise from end to end. Soak in a large bowl filled with 4 cups water and 1 teaspoon salt 5 minutes. (This makes peel easier to remove.) Remove tough outer peel, using a paring knife if necessary, and cut plantains into 1 1/2-inch pieces. Cook, covered, in a 2- to 3-quart saucepan of boiling salted water until tender, about 20 minutes. While plantains cook, cook bacon in a 10-inch heavy skillet over moderate heat, stirring occasionally, until crisp, about 4 minutes. Add onion and cook, stirring, until softened and browned, about 10 minutes. Reserve 1 tablespoon of mixture for garnish, then add milk, pepper, and remaining 1/2 teaspoon salt (mixture may appear curdled). Remove from heat and keep warm, covered. Drain plantains in a colander and return to saucepan. Reheat milk mixture and mash plantains with a potato masher, adding hot milk mixture and butter. Sprinkle reserved bacon and onion on top.
Preparation Using a sharp large heavy knife, cut ends off plantains and slit through peel lengthwise from end to end. Soak in a large bowl filled with 4 cups water and 1 teaspoon salt 5 minutes. (This makes peel easier to remove.) Remove tough outer peel, using a paring knife if necessary, and cut plantains into 1 1/2-inch pieces. Cook, covered, in a 2- to 3-quart saucepan of boiling salted water until tender, about 20 minutes. While plantains cook, cook bacon in a 10-inch heavy skillet over moderate heat, stirring occasionally, until crisp, about 4 minutes. Add onion and cook, stirring, until softened and browned, about 10 minutes. Reserve 1 tablespoon of mixture for garnish, then add milk, pepper, and remaining 1/2 teaspoon salt (mixture may appear curdled). Remove from heat and keep warm, covered. Drain plantains in a colander and return to saucepan. Reheat milk mixture and mash plantains with a potato masher, adding hot milk mixture and butter. Sprinkle reserved bacon and onion on top.