Mustard-Shallot Vinaigrette

"Store-bought salad dressings are an automatic shortcut for many cooks. But with their sweeteners and stabilizers, they aren't worthy of a well-made salad, whether your tastes run to iceberg and romaine or mizuna and mesclun. And — revolutionary notion ahead — they aren’t really more convenient than a basic vinaigrette like this one, made in big batches from real ingredients, which can also live happily and indefinitely in your refrigerator door. Featured in: Magic, With Four Main Ingredients...."