'Dre Masso's recipe, sufficient for 25 oz: mix 15 kaffir lime leaves and 17 oz of caster sugar in a saucepan, then add 25 oz of still mineral water. Bring the mixture to a boil and stir until the powder is dissolved. Then reduce the heat and boil for 5 minutes until the syrup thickens. Remove from heat and leave to cool. Pour the resulting syrup into a bottle and store in refrigerator for 4 weeks.'