Butternut Squash Soup

Name: Butternut Squash Soup
Ingredients: 2 pounds frozen butternut squash; 1 onion; 1/2 cup celery; 1/2 cup carrot; 1 quart low sodium chicken stock; 2 tablespoons maple syrup; 3 tablespoons corn starch; 2 sprigs thyme; 1 tablespoon ancho chili powder; 3 tablespoons butter; Optional garnish: sunflower seeds, pomegranate arils, sherry vinegar