Place the julienned apple into a bowl with the balsamic vinaigrette. Refrigerate for at least one hour to marinate.
Cook bacon in the microwave or in a skillet over medium-high heat until browned. Drain, and crumble.
In a salad bowl, combine the blue cheese, pecans, bacon and romaine lettuce, and toss to blend. When ready to serve, pour the apples and dressing over the top.