Apple Sausage Stuffing

Name: Apple Sausage Stuffing
Ingredients: 1 (16-ounce) loaf sourdough bread; 5 tablespoons unsalted butter; 2 medium yellow onions; 1/2 medium fennel bulb (about 8 ounces); 2 stalks celery (about 6 ounces total); 2 cloves garlic; 2 medium apples, such as gala, honeycrisp or pink lady (about 1 pound total); 1 small bunch fresh sage; 1 small bunch fresh thyme; 1 small bunch fresh parsley; 1 pound uncooked pork sausage, preferably bulk; 2 1/4 teaspoons kosher salt, divided, plus more as needed; 1/4 cup dry white wine (optional - see Recipe Note); 1 1/2 cups low-sodium chicken broth; 1 large egg