Soak tapioca pearls in cold water for 2 hours till they swell. Discard water.
In a medium saucepan, heat milk on medium heat, till warm.
Add tapioca pearls, sugar and cardamom pods and stir.
The pudding wil begin to thicken after around 15 minutes. Continue to stir for a full 35 minutes.
When the pudding looks thick like a rice pudding, take off the heat and allow to cool.
Optional: Line your ramekins / glasses with a thin layer of slivered pistachios.
When cool, transfer pudding into ramekins / glasses and refrigerate for at least 4 hours, and ideally, overnight.