This will make 1 cup and keep well in the fridge for two weeks. For a super quick and delicious salad, mix 4 Tbsp. of dressing with 4 cups of watercress (tough stems removed) and toss with shaved Parmesan.
4 Tbsp. Dijon mustard
3 Tbsp. apple cider vinegar or freshly squeezed lemon juice
1 clove garlic, minced or finely grated
1 cup olive oil
Mix all the ingredients and store in a small glass jar.