• Peel and chop green plantains into small chunks.
• Add to salted boiling water, and cook for 20 minutes, or until plantains are fork tender.
• Drain, but reserve 1 cup of the cooking liquid. 
• In a bowl, mash the plantains, adding the cooking liquid and one cup of very cold water (this prevents the mangú from becoming too sticky). 
• Add the butter, salt and pepper. 
• Serve with seasoned red onions (recipe below), fried queso blanco and salami, to your taste.

Seasoned Red Onions:

• Slice half of a red onion into strips. 
• Add two cups boiling water and cook for about five minutes. 
• Remove from heat and drain. 
• Add 1 tbsp. white vinegar, salt and pepper to taste. 
• Top the mangú with the red onions.