This is the original recipe:
1 1/4 – 2 ounces gin
1/2 ounce dry vermouth
green olive
Shake with ice. Strain into a cocktail glass. Garnish with a green olive.
These days unless you specify, most bars will serve you a vodka martini. Ian Fleming’s James Bond made this popular. Also, before the early 1960’s martinis were stirred.
Always let your bartender what kind of liquor or brand you prefer.