Preheat oven to 375 degrees F.

Heat a large saute pan, add butter, and add the leeks and celery. Saute for 3 minutes and add the mushrooms. Cook until the mushrooms are tender, about 5 minutes and add the herbs and shallots, cooking for 2 more minutes. Add the stock and bring to a simmer. Season with salt and pepper, and pour over the bread crumbs in a mixing bowl. Mix well and cool.

Butterfly the turkey breast open with a sharp boning knife. Using a meat mallet, pound the meat to expand it and make it of an even thickness. Spoon the stuffing lengthwise across the breast and roll up, tucking in the meat at each end. Tie the roulade with butchers' twine.

Season with salt and pepper, and bake for 45 minutes to 1 hour, or until a thermometer reads 150 degrees in the center. Remove and allow to rest for 10 minutes before removing the twine and slicing. Serve with Cranberry Coulis.

Place the ingredients in a non-reactive saucepan and bring to a simmer. Cook until the cranberries have burst, about 20 minutes and transfer to a blender. Blend until smooth, season, and reserve.