What garnish is typically used in a Gibson cocktail?

In a Gibson cocktail, the traditional garnish is a cocktail onion. This is a defining characteristic of the drink, which is typically made with gin and dry vermouth, stirred and served chilled. The onion adds a distinct flavor that complements the botanicals of the gin, offering a unique twist compared to similar cocktails like the martini, which usually features an olive or lemon twist as a garnish.

While some garnishes, such as olives and lemon twists, may be common in other drinks, the Gibson specifically calls for the onion, making it an essential element in defining the cocktail's identity. The presence of three cocktail onions can also enhance the drink's visual appeal and create a stronger onion flavor, which is integral to the overall experience of enjoying a Gibson.