Sebastian M. answered 12/02/19
Neuroscience graduate w/ experience tutoring high school students
Hi there Alizabeth!
Given that Hernán Cortés was a 16th century conquistador, I find it odd that the question asked of you was with regards to his favorite food.
My first piece of advice is this: try consulting your textbook or class materials, because your teacher must have asked this of you for a reason?
Alas, if you do not find anything, here is my two cents after skimming "Food for Thought: A Taste of México in Cortés's Segunda Carta-Relación" by Irene López-Rodríguez of the University of Ottawa.
He was a military man, so food reviews (i) prioritized functionality for his troops, (ii) were biased by his intentions to mask the brutal nature of war, and (iii) biased by his need to appease Charles V of Spain. However, there are observations of his that point to an appreciation of cacao (the cocoa bean used for chocolate) as well as tlacoyo, a thick corn dough tortilla often filled with other foods (e.g. beans or pork) which dates to the pre-conquest era. If you look at the source mentioned above, whose PDF can be found for free after a quick google search, there are quotes regarding cacao, and other sources (e.g. NPR) talk about Cortes and his encounters with tlacoyo.
Tough question; hope this helps, though!