1. Place the mustard, honey, vinegar, and blacken in a bowl, and whisk until blended. Measuring the mustard first, gives a slippery surface for the honey to come out of the measuring spoon easily.
2. Slowly drizzle the oil into the bowl while whisking vigorously. Taste for sweetness and add a little more honey to suit your taste. Don't be concerned if it tastes real hot at this time, because the sour cream and mayonnaise will remove most of the heat.
3. Place the sour cream and mayonnaise in another bowl. Whisk it together, then whisk in the vinaigrette. You'll find that the heat is gone, leaving you with a real nice smokey flavor from the blacken