In a small mixing bowl, whisk together the mustard and vinegar. Pouring slowly, add a thin stream of avocado oil to the bowl, whisking with the other hand. Continue to whisk until all of the oil has been poured into the bowl and the ingredients have come together homogeneously. Season with salt and pepper.
Serve over your favorite green salad.
You can also use your favorite vinaigrette recipe and substitute avocado oil for the oil.