From Castle Street Cafe, Great Barrington
3 cups soybean oil
1 cup red wine vinegar
1½ tablespoons Dijon mustard
1 tablespoon minced shallot
1 egg yolk
Salt and pepper to taste
Combine egg yolk, mustard, shallot and 1/3 cup of the vinegar in a mixing bowl. Whisk together well.
Slowly add the oil, just a little bit at a time, whisking well before each addition of oil. If you add the oil too quickly, the dressing will break.
Alternate adding the oil with the remaining vinegar, whisking well with each addition.
Season with salt and pepper. Store refrigerated.