Winter Squash Soup with Roasted Pumpkin Seeds

Name: Winter Squash Soup with Roasted Pumpkin Seeds
Ingredients: 4 tablespoons unsalted butter; 1 medium onion, coarsely chopped; 1 celery rib, coarsely chopped; 2 garlic cloves, coarsely chopped; 1 cup dry white wine; 1 quart chicken stock or low-sodium broth; 1 quart water; 4 pounds kabocha or butternut squash—peeled, seeded and cut into 1-inch cubes; Salt and freshly ground white pepper; Large pinch of freshly grated nutmeg; Salted roasted pumpkin seeds, honey and diced cucumber, for garnish (optional)