This dressing is more complex with the fragrant, earthy sunflower oil as its base, but you could substitute another flavorful oil, such as extra-virgin olive or walnut oil, with great results. Dried herbs work well in a dressing you plan to keep around a few days. If you prefer fresh herbs, use at least 1 tablespoon of any soft herb.
To read the accompanying story, see: Neutral vegetable oil is boring. Nutty, buttery, cold-pressed sunflower oil is here and ready to be tasted.
Make Ahead: The vinaigrette can be refrigerated in an airtight container for up to 1 week.
Combine the oil, both vinegars, the shallot, sour cream, dried basil and oregano, salt and a pinch of the pepper in a jar with a tight-fitting lid.
Seal and shake vigorously to form an emulsified vinaigrette. (Alternatively, whisk in a mixing bowl or puree in a food processor.)
Taste, and add more salt and/or pepper. as needed.