Our favourite recipe is by Matt Seigel...
1 ounce London Dry gin
1 ounce Carpano Antica sweet vermouth
1 ounce Campari
Orange twist, for garnishing
1. Into each pre-chilled glass, pour the gin, vermouth, and Campari.
2. Fill each glass with large ice cubs. Adding the ice last prevents over-dilution of the alcohol.
3. Stir gently to combine, and garnish with the orange twist.
Recipe link below