Answer:
The Cuban sandwich is (of course) from Cuba, it became popular in the United States with the Cuban community in Miami and Tampa, Florida.
It is a practical and easy to prepare food.
The main ingredients of the Cuban sandwich are:
-1 loaf of bread (Cuban bread, but any bread is good, as well)
-3 or 4 slices of roasted pork.
-3 slices of ham or cooked ham.
-3 slices of Swiss cheese.
-Pickled cucumber (also called pickles)
-Mustard
-Butter.
The only ingredient that does not appear in this list is chorizo.
Therefore, the answer is:
Chorizo