Patacones (known as tostones in Central America) are twice fried rounds of green plantain. Fried green plantain (plátano verde) is starchy and sweet, and absolutely fantastic dipped in creamy aji amarillo sauce. I like to use plantains that are still green but just starting to ripen (with a touch of yellow on the skin). Plantains become sweeter and less starchy as they ripen, but they also lose their firmness.
- Slice the ends off of each plantain, then slice unpeeled plantains crosswise into 1 1/2 wide circles. Place plantain slices in a bowl of salted water to soak for 1 hour.
- Peel the plantain slices. If the peel does not come off easily, make a slit through the skin with a sharp knife first, and then peel it off. Place the peeled plantain slices on paper towels and pat dry.
- Heat 1-2 inches of vegetable oil in a heavy skillet to 350 degrees. Place plantain slices in the oil and cook until golden (plantain should sizzle gently), working in batches if necessary. Drain on paper towels.
- Use the bottom of a glass or bottle to smash/flatten the slices of plantain into disks about 1/3-1/2 inch thick.
- Return flattened plantains to the hot oil and fry until deep golden brown. Drain on paper towels, and sprinkle generously with kosher salt.
- Serve plantain warm with aji sauce for dipping.