If Rubio's is the David to Chipotle's Goliath, David is catching up.

The San Diego-born chain, founded by a college-aged surfer and made famous for its fish taco recipe, rose to fame when it toppled Chipotle to become the top-rated Mexican restaurant chain in America in a 2015 Consumer Reports survey.

Since then, Rubio's has expanded from 163 locations on the West Coast to 206 nationwide, with an East Coast launch planned for 2017. By comparison, Chipotle has over 2,000 restaurants across the US.

We visited Rubio's in Vallejo, California, to see what the buzz is about.