2 teaspoons white-wine vinegar
2 teaspoons Dijon mustard
1/2 teaspoon salt, or to taste
1 1/2 teaspoons sugar
1 tablespoon mild olive oil
1 large seedless cucumber (usually plastic-wrapped; 1 lb), peeled
2 tablespoons chopped fresh dill

Whisk together vinegar, mustard, salt, and sugar in a bowl, then add oil in a
slow stream, whisking.
Halve cucumber lengthwise and remove seeds with a small spoon, then cut halves
crosswise into 1/8-inch-thick slices.

Add cucumber and dill to vinaigrette, tossing to coat.

Makes 4 servings.