Negroni
The Negroni is a popular Italian cocktail, made of one part gin, one part vermouth rosso (red, semi-sweet), and one part Campari, garnished with orange peel. It is considered an apéritif.
A properly made Negroni is stirred, not shaken, and (classically) built over ice in an old fashioned or ‘rocks’ glass and garnished with a slice of orange. Outside of Italy an orange peel is often used in place of an orange slice, either is acceptable though an orange slice is more traditional.