Treat and peel 1 large cucumber.
Remove all the tough seeds.
Chop the rest and put it into an electric blender with 2-3 tablespoons fresh curds.
Whizz for a few seconds to get a smooth paste.
Add more curd, 1/2 teaspoon salt, a few mint leaves, pepper to taste and 1/2-3/4 teaspoon sugar.
Blend again, just to mix thoroughly.
Add a few teaspoons water if you prefer it thinner.
Remove from the blender and chill well before serving.
Garnish, if you like, with a fresh mint leaf.