In the U.S., it’s impossible to bite into the crunchy goodness of a hard shell taco without thinking of Taco Bell: The combination of a soft, gooey inside counterbalanced with the crunch of a tortilla chip shell is what food porn dreams are made of. Not to mention that they’re inexpensive and nowadays, thanks in large part to Glen Bell, the founder of Taco Bell, ubiquitous. But of course, Bell was an American entrepreneur, and the hard shell taco is Mexican cuisine. So where did they come from, and how did this Mexican food staple become the symbol of an American fast food chain? To find out, I spoke to a food historian, a Los Angeles Times reporter and the grandson of the woman who founded the restaurant that inspired Bell to create his taco kingdom...