Jakub Kozlowski’s recipe, good for 7 oz: In a saucepan, mix the pulp of 5 limes, the zest of 1 lime, 7 oz of still mineral water and 5 oz of sugar. Infuse for 12 hours at room temperature, then strain and add 20 mint leaves. Put the mixture in the fridge and infuse for 12 more hours. Bottle the resulting cordial and store in fridge.