Every family needs a house dressing that can be made in a jiffy for tossing with salad greens. Now that everyone buys balsamic vinegar, a vinaigrette made with the heady stuff is one of the most popular dressings around. And for good reason. It's versatile and tasty, with a touch of sweetness. I use a blender, which produces a thicker vinaigrette than you might expect. Allow 2 to 3 tablespoons of dressing per serving. A cup should easily be enough for 6 to 8 servings of mixed greens.