Step 1

Place some crushed ice into a wide-rimmed glass, and set aside.

Step 2

Place 1 cup of crushed ice into a Boston-style cocktail shaker. Pour in the vermouth and swirl it around, making as much contact as possible with the ice. Using a strainer, pour the vermouth out. Add the gin and stir well to combine.

Step 3

Remove the ice from your serving glass and add the olive. Using the strainer, pour the gin into the serving glass.