Classic Dominican Mangú

1. Start the onions first. Add the sliced red onion to a bowl. Stir together vinegar, warm water, and salt (and sugar if using), then pour it over the onions. Toss well so the onions are mostly submerged. Let sit while you cook the plantains, at least 10 minutes, stirring once or twice if you think about it.
2. Optional warm-onion method (more traditional vibe). After the onions have soaked for 10 minutes, heat 1 tablespoon oil in a small skillet over medium heat. Add the onions with a splash of their liquid and cook 2 to 3 minutes, just until softened and glossy. Turn off the heat and set aside.
3. Peel and cut the plantains. Trim both ends. Score the peel lengthwise in a few lines, then pry it off with your thumb or the tip of a spoon. Cut plantains into 2-inch chunks.
4. Boil until tender. Put plantain chunks in a medium pot and cover with water by about 1 inch. Add 1 1/2 teaspoons salt (this salt is for the plantains). Bring to a boil, then reduce to a steady simmer and cook 12 to 15 minutes, until very tender when pierced with a fork.
5. Reserve water, then drain. Scoop out 1 cup of the cooking water and set it aside. Drain the plantains well.
6. Mash while hot with butter and cooking water. Return plantains to the pot (off heat) or to a large bowl. Add butter and mash while the plantains are still hot. Add hot reserved cooking water a splash at a time until the texture is creamy and spoonable. Taste and add more salt if needed.
7. Serve. Spoon mangú into bowls and top with the onions (drain a little liquid first so it does not get soupy). If you want the full experience, add a fried egg, sliced avocado, or some sautéed salami on the side.

Matt’s tiny tip: If your mangú cools down and tightens up, it is not ruined. Add a tablespoon or two of hot water and stir like you mean it.