How a Single Food Truck Helped Build a Multi-Million Dollar Taco Empire This founder started with $18,000 in his bank account. Now he runs a $4.5 million fast-casual-food brand.

In five years, St. Louis native David Choi went from having $18,000 in his bank account to running a $4.5 million Korean-Mexican fast-casual-food chain with four restaurants and a food truck enterprise. Here's how he did it.

1. Navigate the humble beginnings.

"I started Seoul Taco at the peak of the recession because I didn't want to work three minimum wage jobs 100 hours a week. I sold my car, cashed out my bank account and found someone selling a food truck in Philadelphia for $40,000. I had $18,000. He sold it anyway because his wife would kill him if he didn't get that thing out of the driveway. I drove back to St. Louis and went to a chiropractor the next day because it gave me excruciating back pain.