Lower the heat to medium low and keep stirring and scraping the sides of the pan after every 10-12 minutes.
Cook the milk for 1 to 1.5 hours, till it is reduced to quarter.
Add sugar, saffron soaked in milk and rose water and cook for another 3-4 minutes.
Pour the rabri in earthen pots for more flavour or else just transfer in a serving bowl.
Garnish with almond and pistachio slivers.
Either serve hot or chill in refrigerator for a few hours before serving.
Use a heavy bottom pan to make rabri.Keep stirring the rabdi after every 10-12 minutes while cooking to make sure it doesn't stick to the bottom of the pan. You can adjust the amount of sugar according to your taste.