Fill an old fashioned glass with ice cubes.
Pour 30ml Campari over the ice.
Add 30ml sweet red vermouth.
Top with a splash of soda water and stir gently to combine.
Garnish with a half orange slice and a lemon zest.
The Americano is the direct predecessor of the Negroni - legend has it that Count Camillo Negroni simply asked for his Americano with gin instead of soda water. It was also famously James Bond's first drink order in the original Ian Fleming novels.
My Bar Shelf reads your shelf and shows you every cocktail you can make from what you already own, including Americano.