Makes 1 cup
1/2 cup olive oil
1/4 cup apple cider vinegar*
2 Tbsp. water
2 Tbsp. prepared Dijon mustard (e.g. Grey Poupon)
1 Tbsp. freshly squeezed lemon juice
*The organic raw kind, if you have it; ordinary cider vinegar will work, too.
Whisk all ingredients together until well combined. Transfer to tightly covered container and shake or stir vigorously just prior to use. Refrigerate unused dressing tightly covered; it should keep for up to several weeks.