Mexican Spanish is peppered with bits of French due to France's occupation of Mexico in the mid 1800's when Napoleon III tried to establish a French Empire of Mexico after the Mexican American war of 1846-48.
Cinco de Mayo is the celebration of Mexico's defeat of the French in 1865. But that was plenty of time for numerous French words, especially French words related to food (no surprise there) to be absorbed into the Mexican language. Yet you'll find virtually none in any of the other versions of Spanish.
I didn't know that! That is really cool, though not surprising, since language has been influenced by colonialism, occupation and other cultural/political blendings for, well, as long as perhaps humans have existed.