Salt in medium bowl with wire whisk, until well blended. Set aside.
Toss 8 cups mixed greens, 1 small red onion, thinly sliced, and 1/2 cup crumbled blue cheese in large bowl. Serve with vinaigrette.
Nutritional information per serving: 418 calories, fat 24 grams, protein 28 grams, carbohydrates 19 grams, cholesterol 62 mg, sodium 713 mg, fiber 3 grams