Butter milk dressing tastes particularly good with cucumber salad, lettuce or lamb's lettuce. Butter milk dressing is very easy and quick to prepare. Pour well chilled butter milk into a bowl and stir in olive oil vigorously with a whisk until the butter milk combines with the olive oil. Season the butter milk dressing with pepper and salt and round off with a pinch of sugar. Chop the parsley as finely as possible, as can be seen in the picture above, and stir into the dressing. To serve, pour the butter milk dressing into a small glass carafe and serve with the salad.