Melt 1 stick butter in a large skillet over medium heat. Cook 1 pound crumbled sausage in the butter. Add 2 cups each diced onion and celery and 1 tablespoon each minced sage and thyme; add salt and pepper and cook 5 minutes. Add 3 cups chicken or turkey broth and 4 cups chopped spinach; bring to a simmer. Beat 2 eggs with 1/4 cup chopped parsley in a large bowl; add 6 cups cubed stale cornbread and 8 cups white bread and 1/3 cup each pine nuts and grated parmesan, then pour in the vegetable-broth mixture and toss. Transfer to a buttered baking dish and dot with butter. Cover and bake at 375 degrees F, 30 minutes; uncover and bake until golden, about 30 more minutes.