Cut the passionfruits in half. Then, scoop out the pulp and seeds into a fine mesh strainer set over a bowl.
Press the pulp through the strainer with a spoon to extract the juice. Set aside.
Make simple syrup by heating sugar and water in a small pot until the sugar dissolves. Let it cool.
Juice the lemons until you have 1 cup of fresh juice.
In the pitcher, combine passionfruit juice, lemon juice, and simple syrup.
After that, add cold water and stir well.
Taste and adjust the sweetness if needed.
Fill glasses with ice and pour in the mocktail.
Finally, garnish with mint leaves and lemon slices.