Butternut Squash Soup With Sage and Parmesan Croutons

Name: Butternut Squash Soup With Sage and Parmesan Croutons
Ingredients: 1 3-pound butternut squash, peeled, seeded, and cut into 1-inch cubes (5 to 6 cups); 3 tablespoons olive oil; 3 teaspoons kosher salt; pinch of freshly ground black pepper; 1 tablespoon butter; 1 large yellow onion, diced (about 1 1/2 cups); 3 stalks of celery, chopped (about 1 1/2 cups); 1 tablespoon chopped fresh sage (about 6 large leaves); 6 cups chicken broth; ½ cup freshly grated Parmesan; Sage and Parmesan Croutons