Coarsely chop the prepared cucumber and place it into a blender or food processor along with the plain yogurt. Process until completely smooth.
Transfer the smooth cucumber-yogurt mixture into a large bowl.
Stir in the chopped nuts, minced fresh mint, your chosen oil, salt, and dry-roasted cumin seeds.
Mix everything together well, cover the bowl tightly, and refrigerate for at least 1 hour to allow the soup to chill and the flavors to meld.
Before serving, stir the chilled soup thoroughly. Ladle it into pre-chilled bowls and garnish each serving with a sprig of fresh mint.
Dry-Roast Your Cumin: Don't skip this!
Tossing cumin seeds in a dry skillet for 1-2 minutes until fragrant releases their essential oils for a deep, smoky flavor that ground cumin can't match.
Chill Your Bowls: Pop your serving bowls in the freezer for 15 minutes before serving. This simple trick keeps the soup perfectly ice-cold from the first spoonful to the last.