Asparagus vinaigrette are delicious and refreshing served as a first course.

Trim asparagus and cook them until tender but still lightly crunchy. Put them in a glass or plastic covered container.
In a measuring cup, put the oil, vinegar, mustard, tarragon, salt and pepper. Whisk until homogeneous and pour over asparagus. Cover and refrigerate 1 to 24 hours. Baste asparagus with the vinaigrette once or twice while marinating.