I just finished this book by Jennifer Crusie and Bob Mayer.  It's hilarious, kind of like a Janet Evanoch style book.

Agnes is  a food critic who has a little temper problem.  She's on her third fiance...she hit the first one in the nose with a frying pan when she caught him cheating on her.  She hit her second fiance in the back of the head when she caught him with another woman on their kitchen table. Now someone is trying to kill her.

Her friend, a former Mob guy, calls his nephew home to help protect her.  The nephew, Shane, is a hitman for the US Government.  Some kind of covert national security agency. 

Agnes also has a bloodhound dog named Rhett that somebody tries to kidnap.  It's set in South Carolina.