Boil the sago in 2 litres of water till it becomes almost transparent, with a small white portion inside.
Strain into a colander and wash well to remove the starch.
Add back into the pan, along with the condensed milk and sugar. Bring to simmer and cook till the sugar melts and the sago looks entirely done.
Add the flavors and switch off. Keep it closed to allow the flavors to mingle.
Enjoy warm or cold...