Mitchells was a popular all-night lunch counter type restaurant in 1920s Paris.  It was owned by Louis Mitchell, a famous black musician and band leader who was one of the earliest “Razz” musicians.  The name was later changed to Jazz.  Louis recorded the first Jazz record in 1922. He played at the Casino de Paris for many years with a group he formed called the Jazz Kings before opening his own club, Mitchells.  Bob & Muriel often had breakfast there after work.