1. Fill a 12-oz highball glass half way up with orange juice. Pour some grenadine syrup carefully… it should go straight to the bottom, not mixing with the orange juice.
2. Gently place two ice cubes on the highball glass and then, in a mixing glass, mix the pisco with a mint liqueur. Pour the pisco/mint mixture very slowly over the ice cubes, so that it floats without mixing with the orange and/or grenadine.
3. You should get a beautifull red-orange-green cocktail. When serving, instruct your guests to drink it from a straw, pulling it up as they drink, in order to get the three different flavours.