Add the celery and shallots to a sauté pan with the butter over medium heat. Cook them until the celery is tender and the shallots are translucent. Set aside.
Add the bread, dates, nuts, celery, shallots, parsley, and seasonings to a bowl and mix to combine.
Slice the turkey breast along the side and fold it open like a book.
Place a piece of plastic wrap over the top of the turkey or place it into a plastic bag. Use a meat mallet to lightly pound out the turkey into an even thickness.
Pour the stuffing mixture into the middle of the turkey breast. Fold it over.
Use several pieces of kitchen twine to tightly secure the turkey.
Place the stuffed turkey breast into a baking dish. Brush the top with olive oil. Season it with 1/2 teaspoon of salt and 1/4 teaspoon black pepper.
Bake the turkey for 45 minutes, or until the internal temperature is 165 degrees.
Allow the turkey to rest for at least 10 minutes before slicing it.