The Alecrin Gin Fizz cocktail recipe made by Guilherme Kilpp Gonzatti:
Add the rosemary leaves to a Highball glass, add the simple syrup (or sugar syrup) and muddle gently. Fill the glass with ice, add the lemon juice and the gin (preferably Tanquaray Ten), give it a good stir and top it with soda water. Club Mate Soda also works wonderfully, if you can find it.
Garnish the Alecrin Gin Fizz with a slice of lemon and some more rosemary.