Chipotle Founder Reveals Why People Thought His Restaurant Wouldn't Work

But Ells said that many thought his idea of making burritos and tacos from a few fresh ingredients wouldn't work.

On an earnings conference call, Ells described the biggest criticism people had with his first restaurant:

"I remember 20 years ago people said, 'Steve, a menu with burritos and tacos, I mean, you're going to have to add new stuff pretty soon,'" Ells told investors. "But it’s the combinations of things that people can make, not only for taste but for diet and people can vary enough over the years during their visits that really keeps Chipotle fresh."

Ells opened the first Chipotle in Denver, Colorado in 1993. Today the chain has more than 1,500 locations.

And while Chipotle might have few ingredients on the menu, there are a mind-boggling number of combinations to be had.

Our math found that 655,360 different options were possible from Chipotle's current ingredients.