Wash and halve the oranges and lemons, then juice them to get about 1 cup orange juice and ½ cup lemon juice. Pour both juices into a pitcher.

Add the fresh mint leaves into the pitcher. Use a muddler or the back of a wooden spoon to gently press and bruise the leaves, releasing their oils into the juice.

Add the honey or agave syrup to the citrus-mint mixture. Stir well until the sweetener is fully dissolved.

Pour in the cold sparkling water and give everything a gentle stir to combine.

Fill each glass with ice cubes. Pour the mocktail mixture evenly into the four glasses.

Garnish each glass with a mint leaf and an orange or lemon slice if desired. Serve immediately.

Optionally, you can substitute honey with sugar for a vegan option or adjust sweetness to taste.

You can mix in other citrus juices like lime or grapefruit for extra flavor.

This mocktail is best served fresh, but you can premix the juice and sweetener and add sparkling water just before serving to keep it fizzy.