Preheat oven to 375F. Arrange squash, cut side up, in large roasting pan. Place garlic cloves in squash cavities. Drizzle oil over. Sprinkle with dried sage, salt and pepper. Cover with foil and bake until squash is tender, about 1 hour 35 minutes. Cool slightly. Peel squash and garlic. Transfer to processor and puree. Combine broth, 1 3/4 cups water and 1 1/2 teaspoons salt in heavy large saucepan. Bring to boil. Gradually whisk in polenta. Reduce heat to medium-low and cook until mixture is very thick and creamy, stirring often, about 20 minutes. Stir in fresh sage and 3 cups squash puree (reserve any remaining puree for another use). Cook until heated through, about 2 minutes. Stir in cheese. Season with salt and pepper. (Can be made 1 day ahead. Cover and chill. Stir over medium-low heat until heated through.) *Available at Italian markets, natural foods stores and some supermarkets. If unavailable, substitute 1 1/2 cups of regular yellow cornmeal, and cook mixture for about 10 minutes. Makes 6 servings. Bon Appetit October 1999 Per serving: 2396 Calories (kcal); 45g Total Fat; (16% calories from fat); 48g Protein; 463g Carbohydrate; 0mg Cholesterol; 3259mg Sodium Food Exchanges: 29 Grain(Starch); 0 Lean Meat; 1 Vegetable; 0 Fruit; 8 1/2 Fat; 0 Other Carbohydrates Converted by MM_Buster v2.0n.