In a medium bowl, whisk
together the vinegar, shallot
, mustard, salt, and pepper. While constantly whisking, add the vegetable and olive oil in a thin, steady stream until they are completely incorporated and the dressing
is emulsified. Stir in the herbs
, and adjust the seasoning, to taste, if necessary. Serve the vinaigrette
immediately or refrigerate in a covered nonreactive container for up to 2 days.