This mustard vinaigrette recipe is one of the simplest variations on the basic vinaigrette formula (3 parts oil to 1 part vinegar or a ratio of 3: 1) and a delicious salad dressing in its own right. Ballpark mustard simply won't do here. For the best flavor possible, a dijon or whole-grain mustard is the way to go. Dijon is made from brown or black mustard seeds, white wine, and seasonings, while whole-grain mustard hasn't been ground to a complete paste, but has partial mustard seeds visible. They both can pack a spicy punch. As far as the oil goes, any oil labeled "Vegetable oil" Or "Salad oil" Is fine for this recipe. You also can use any light, neutral-flavored oil like safflower, canola, or soybean oil.