Cheese & Onion
A popular term–so called as it is yellow and green (and red)–for the Oxford Handbook of Clinical Medicine, one of the most widely used medical books in the English-speaking world. It debuted in 1985, is aimed at medical students and junior doctors, and covers all aspects of clinical medicine. and is currently in its 9th edition.
Reference BMJcareers 18.02.06, p70