Mince ½ shallot, aim for 1 tablespoons-worth of minced shallot. Using a mason jar with a tight fitting lid, add theminced shallots, ¼ cup of champagne vinegar, 1 teaspoon of Dijon mustard, a pinch of kosher salt, a pinch of freshly ground black pepper,and ½ cup of extra-virgin olive oil. Seal tightly and shake to emulsify. If you don’t have a sealable mason jar, in a large bowl combine all of the ingredients (except for the extra-virgin olive oil) and slowly whisk in the olive oil until emulsified.
Keep the vinaigrette covered in the refrigerator for up to a week. Let the salad dressing come to room temperature before shaking and drizzling it over your greens.