Is there "Pret a Manger" quality chicken and avacado sandwich in west side LA?
Believe it or not, Cheesecake Factory has a great grilled chicken with avocado sandwich. Another place, Barney's (there's one on San Vicente and one at the 26th Street Mart),
The Counter has this on their menu, too. Buon Giorno on Santa Monica Blvd at 15th Street has a great one, panini style.
Actually, it's a pretty easy sandwich to find.