Preparation Cut ends from each plantain with a sharp small knife, then cut a lengthwise slit through peel. Cut plantains crosswise into 1-inch-thick pieces and, beginning at slit, pry off peel. Heat 1/2 inch oil in a deep 10- to 12-inch heavy skillet over medium heat until just hot enough to sizzle when a piece of plantain is added. Fry plantains in 2 batches, turning occasionally with tongs, until tender and just golden, 5 to 7 minutes per batch. Transfer plantains to paper towels to drain, reserving oil in skillet. Flatten each plantain to 1/4 inch thick with a tostone press or bottom of a heavy saucepan. Stir together warm water and 1/2 teaspoon salt in a bowl. Heat reserved oil over medium heat until it shimmers. Dip a flattened plantain in salted water and gently place, without patting dry, in hot oil. (Plantains will not spatter.) Repeat with several more pieces and fry plantains (without crowding) in 4 or 5 batches, turning occasionally, until golden, about 3 minutes per batch. Transfer with tongs to clean paper towels to drain. Season with salt and serve immediately.
Preparation Cut ends from each plantain with a sharp small knife, then cut a lengthwise slit through peel. Cut plantains crosswise into 1-inch-thick pieces and, beginning at slit, pry off peel. Heat 1/2 inch oil in a deep 10- to 12-inch heavy skillet over medium heat until just hot enough to sizzle when a piece of plantain is added. Fry plantains in 2 batches, turning occasionally with tongs, until tender and just golden, 5 to 7 minutes per batch. Transfer plantains to paper towels to drain, reserving oil in skillet. Flatten each plantain to 1/4 inch thick with a tostone press or bottom of a heavy saucepan. Stir together warm water and 1/2 teaspoon salt in a bowl. Heat reserved oil over medium heat until it shimmers. Dip a flattened plantain in salted water and gently place, without patting dry, in hot oil. (Plantains will not spatter.) Repeat with several more pieces and fry plantains (without crowding) in 4 or 5 batches, turning occasionally, until golden, about 3 minutes per batch. Transfer with tongs to clean paper towels to drain. Season with salt and serve immediately.