Combine 1 cup
(250 ml) of the milk with the rest of the
ingredients, except the pistachios, and blend to a
paste in a blender or food processor. Strain
through a muslin or cheesecloth-lined sieve.
Add the remaining
milk to the strained mixture and check for
sweetness. Chill for 3 to 4 hours to allow the
flavors to combine and serve in tall glasses, each
garnished with a little ground pistachio.