Take 500 grams of fresh blackberries and wash them thoroughly. Set aside a few blackberries for garnishing later.
In a blender, blend the washed blackberries until smooth. Pass the puree through a fine sieve to remove any seeds. Keep the blackberry puree aside.
Take 1 kg of fresh, thick curd (yogurt) and place it in a muslin cloth. Tie the cloth and hang it for 3-4 hours to drain the excess whey. This will give you thick and creamy hung curd.
In a mixing bowl, combine the hung curd, blackberry puree, 150 grams of powdered sugar, and 1/2 teaspoon of cardamom powder. Mix well until smooth and creamy.
Refrigerate the blackberry shrikhand for at least 2 hours before serving.
To serve, scoop the chilled shrikhand into individual bowls, garnish with reserved blackberries and a few chopped pistachios.