Cornbread stuffing with sausage and apples - chinese grandma

Ingredients

• 4 cups stale bread cubes (a light-textured bread is best)
• 4 cups cornbread cubes (cornbread recipe in notes below)
• 1/2 pound Italian sausage
• 6 tablespoons butter
• 2 cups chopped celery (4-5 stalks)
• 1 cup chopped onion (1 medium)
• 2 cups apple (2 large apples, no need to peel)
• 3/4 teaspoon kosher salt, or to taste
• 1/2 teaspoon pepper, or to taste
• 1 teaspoon sugar (optional)
• 1 teaspoon dried thyme
• 1/2 teaspoon dried sage
• 1/4 cup minced fresh parsley
• 2 cups (approximately) chicken broth