Spanish rice, ironically, is not a Spanish at all -- it originated in Mexico (and is sometimes referred to as Mexican rice). Spanish conquistadors introduced rice to Mexico in the 1500s, hence the name; it soon took on a life of its own, evolving into an economical "peasant" dish that turned bits of leftovers into a full meal. So we can thank Mexican chefs for the popularity of this deliciously versatile dish that has become an American favorite.