In 2000 McDonald’s decided to diversify and bought the Boston Market (Chicken!) chain. The same initiative spurred investments in Chipotle Mexican Grill Inc., Donato’s Pizza and Fazoli’s Italian fast-food. But now the company is refocusing on its core burger business and Boston Market has just been sold to Sun Capital Partners who had also picked up the Fazoli’s stake. Chipotle was taken public in 2006 and McDonald’s divested its investment. Donato’s was sold back to its founders in 2003. Sun Capital Partners is a private investment firm whose other food holdings include Hickory Farms.