It doesn’t seem like a simple sandwich should be able to raise issues of gentrification, cultural appropriation, and even racism. But all of these themes are at play in “Hometown Hero: The Legend Of New York’s Chopped Cheese,” a surprisingly heady 18-minute documentary from the editors of First We Feast. The focus here is on a culinary cult favorite from Harlem and the Bronx. Consisting of ground beef, melted cheese, and assorted toppings served on a hero roll, the chopped cheese sandwich has long been a staple of bodegas, prized for its delicious taste and low price. But now, the sandwich is poised to go mainstream, after having been “discovered” by curiosity-seeking outsiders and featured on Anthony Bourdain’s Parts Unknown as well as on Insider’s food section. Is the chopped cheese sandwich finally getting its long-overdue moment in the spotlight, or is this just another example of something pure being ruined by hipsters? Opinions vary.