The above cocktail is called the Adonis. It has a mere three ingredients (four, if you count the ice), and making it is a good excuse to use up the sweet vermouth if you have it on hand.
This low-alcohol aperitif is a classic, but this version comes from Komi restaurant in Washington, DC, and was published by Food & Wine magazine.
1 1/2 ounces fino sherry
1 ounce sweet vermouth
2 dashes orange bitters
In a cocktail shaker, combine fino sherry, sweet vermouth and orange bitters. Add ice and stir well. Strain into a chilled cocktail glass.