Whisk vinegar, pomegranate molasses (or cranberry juice concentrate), salt and pepper in a small bowl. Slowly whisk in oil.
Ingredient note: Pomegranate molasses lends a bright, tangy flavor to many Middle Eastern and Persian dishes. (Do not confuse it with grenadine syrup, which is very sweet and contains little or no pomegranate juice.) Bottled molasses is sold in Middle Eastern markets and some large supermarkets.
