On a recent day, KFire owners Ben Kim and Eddie Hwang had 13 catering orders for lunch and not enough delivery drivers at their fast-casual Korean barbecue restaurant in Old Town. So Kim made an unexpected delivery to the University of Chicago Law School in Hyde Park. “Everyone wants lunch at the same time,” he said.For the two friends, it was just another day of navigating the challenges of running restaurants. But KFire’s existence was tested …