He deals with the customers in a very 'professional' way. = He is very 'professional' in dealing with the customers.
a golf/tennis 'professional' [=a skillful golf/tennis player whose job is to teach other people how to play]
I was impressed by the calm and 'professional' way she handled the crisis.
(..) Have you seen the place? Mm-hmm. It's pretty good. It's a little too good. Corporate must have sent in a professional. I don't know why some body's Gunning' for my job, But, look... let's Remain team, okay? 'Cause if I go, we all go. (..)2003 Elf