Dominican Mangú with Pickled Red Onions

For the mangú

• 4 green plantains, peeled and cut into chunks
• 1 tbsp olive oil
• 0.5 cup reserved cooking water
• salt, to taste

For the pickled onions

• 1 red onion, thinly sliced
• 0.5 cup apple cider vinegar
• 1 tsp salt
• 1 tsp sugar
• 0.25 cup water

1. Combine vinegar, salt, sugar, and water; pour over the sliced red onion and let pickle while you prepare the plantains.
2. Boil the plantain chunks in salted water 18-20 minutes until very tender. Reserve 1/2 cup of the cooking water, then drain.
3. Mash the hot plantains with olive oil and reserved cooking water until smooth and creamy, adding more liquid as needed.
4. Season with salt to taste.
5. Top the mangú with the pickled red onions and serve warm.