Fine bread crumbs make a more elegant stuffing than bread cubes do.
1/2 lb. butter
3 medium yellow onions, peeled and finely chopped
1 head celery, trimmed and finely chopped
Leaves from 1 large bunch parsley, finely chopped
1/2 cup finely chopped fresh sage leaves (about 6 large sprigs)
Salt and freshly ground black pepper
10 cups fine fresh sourdough bread crumbs
1/2 cup Chicken Stock
Preheat oven to 350°. Melt butter in a large heavy-bottomed skillet over medium-low heat. Add onions and cook without browning, stirring often, until very soft, about 20 minutes. Add celery, parsley, and sage. Generously season with salt and pepper and cook, stirring often, for 5 minutes more. Remove from heat and transfer to a large bowl.
Add bread crumbs to onion–celery mixture and toss until well combined. Add chicken stock and mix until stuffing is just moist but not packed together. Adjust seasonings.
Spoon warm stuffing into turkey, truss, and bake. Or put stuffing into a buttered baking pan and bake until hot and golden on top, 30–45 minutes.