Boil the plantains in water with a teaspoon of salt. When soft, drain the plantains (leave at least ½ cup of water). Smash the plantains add water and butter to taste. Cut the onions in slices and sauté them in olive oil and ½ teaspoon of vinegar. Place the onions on top of the plantains.
Cheese: Cut the cheese in a rectangular shape and fry both sides until golden brown.
Salami: Cut the salami into slices and fry both sides.
This dish is traditionally served with fried (sunny side up) eggs.