In small bowl, beat vinaigrette ingredients with wire whisk. Cover and refrigerate up to 24 hours.
In 12-inch nonstick skillet, melt butter over high heat. Add pears and sugar; cook and stir 6 to 8 minutes or until fruit is tender and golden. Cool slightly.
In large salad bowl, toss greens, onion and half the vinaigrette. Transfer to large platter. Arrange pears, pecans and cheese over greens. Drizzle with remaining vinaigrette. Serve immediately.