Bring milk to a boil in a wide heavy-bottomed pot over medium-low flame.
As cream layer forms on top, gently push it to the sides of the pot using a spatula.
Repeat process for 35 minutes until milk reduces to one-third volume and turns thick.
Stir in sugar, cardamom powder, and cream layers scraped from sides; cook for 3 minutes.
Garnish with chopped almonds and pistachios; serve warm or chilled.