Winter Squash and Gruyère Gratin

Name: Winter Squash and Gruyère Gratin
Ingredients: 2 medium butternut squash (1 1/2 pounds each); 3/4 teaspoon salt; 3/4 teaspoon freshly ground pepper; 1 medium leek, white part only, coarsely chopped (1/2 cup); 1 teaspoon olive oil; 1/2 cup dry white wine; 1/2 cup low-sodium chicken stock or canned broth; One 12-ounce can evaporated skim milk or 1 cup whole milk; 1/2 teaspoon sugar; 4 ounces Gruyère cheese, grated (about 1 cup); 2 ounces of a baguette (thinly cut into 8 small slices) or 2 slices peasant bread (cut into 4 equal pieces), toasted; 1 tablespoon plus 1 teaspoon grated Parmesan cheese; 8 basil leaves, shredded