When a person learns to do one job and specializes in that one job, she gets really good at it.
The restaurant specializes in fresh local seafood.
He specializes in discreet, highly contained domestic counter insurgency and counterterrorism operations.
Gilberts specializes in wood fired steaks and seafood.
The menus change seasonally, and the establishment specializes in fish and game dishes, with sophisticated fare like escargot and sweetbreads.