In a small bowl, whisk together the mustard and vinegar.
Whisk in the olive oil and then the hazelnut oil. Season with salt and pepper to taste.
In a large bowl, place the sliced pears and ½ of the dressing and let the pears marinade in the dressing for about an hour.
Add the greens and the bacon and gently toss. Add more dressing if necessary.
Sprinkle with the nuts and serve.