Begin by rolling fresh lemons on the countertop to release their juices. Cut the lemons in half and use a citrus juicer to extract juice until you have one cup of bright, tangy lemon juice.

In a large pitcher, combine the freshly squeezed lemon juice with sweetened condensed milk. Stir vigorously for one to two minutes until lump-free.

Gradually pour in ice-cold water, stirring consistently. Taste and adjust sweetness with simple syrup if necessary.

Chill in the refrigerator for about 30 minutes or serve immediately over ice.

Pour the chilled lemonade into tall glasses filled with ice cubes. Garnish each glass with lemon slices and mint leaves.