Soak the mango in water
Boil the milk, then add lemon juice, and let the milk curdle
Squeeze and remove the excess water from the curdled milk
Add the curdled milk to the blender along with mango chunks, rock sugar, cardamom, and milk
Blend until smooth
Pour the mixture onto a serving tray
Garnish with mango chunks and watermelon seeds
Refrigerate for 1 hour
Serve chilled
