Preheat oven to 400ºF. Place bread cubes on a baking sheet, and toast 5 to 7 minutes or until barely golden.
Melt butter in a large skillet. Add leeks and celery, and cook over medium heat for 3 minutes or until softened. Add pine nuts, and cook a few minutes more. Transfer to a large bowl and add bread cubes, herbs, salt, pepper, and chicken broth. Toss well and adjust seasoning.
Reduce oven to 325ºF. Transfer stuffing to baking dish, and bake 20 minutes until heated through and lightly browned on top.