Chicago police said shortly after noon in the 2000-block of West Shakespeare, a 49-year-old man was approached by two men who demanded his car.
At least one of those men pulled out a gun and shot, striking the man in the leg, police said. He was taken to Illinois Masonic Hospital for treatment; police said he was reported to be in good condition.
The restaurant's other co-owner confirmed it was his business partner who had been shot, and said the thieves also stole his phone.
No one is currently in custody. An investigation by Chicago police is ongoing.