Roasted Winter Vegetables With Cheesy Polenta

Name: Roasted Winter Vegetables With Cheesy Polenta
Ingredients: 1/2 teaspoon garlic powder; 2/3 cup finely shredded Parmesan cheese, preferably Parmigiano-Reggiano; 4 cups cubed peeled butternut squash, (1 1/2-inch chunks); 1 cup water; 1/4 teaspoon salt; 2 tablespoons extra-virgin olive oil; 1 medium onion, sliced; 3/4 teaspoon freshly ground pepper, divided; 4 cups cauliflower florets, (see Tip); 3/4 cup cornmeal; 2 1/2 cups vegetable broth, or reduced-sodium chicken broth; 1 teaspoon chopped fresh rosemary, or 1/2 teaspoon dried