-diced POLENTA: In a heavy medium saucepan, bring 3 1/4 cups of water to a boil over high heat. With a large wire whisk, slowly whisk in the cornmeal in a steady stream, whisking rapidly and constantly to prevent lumps. Reduce the heat to medium-low and cook, stirring frequently with a wooden spoon, until very thick, about 15 minutes. Remove from the heat and stir in half of the Parmesan cheese. Coat two 9-inch square baking pans with nonstick cooking spray. Spread the polenta evenly in the two pans. Place the pans in the freezer for 20 minutes to chill. Heat the oil in a medium saucepan over medium heat. Add the onion and garlic; saute for 1 minute. Cover and let steam 10 minutes, stirring occasionally. Add the cooked ground beef, tomatoes, tomato paste, and seasonings. Bring to a boil. Reduce heat to medium-low and cook for 15 minutes. Preheat the oven to 450F. When the polenta has chilled, spread half of the meat sauce evenly over one layer in pan. Top with half of the mozzarella and half the remaining Parmesan cheese. With your fingers, loosen the edges of the polenta in the other pan. Invert the second pan over the first so that the drops out into place.. Spread evenly with the remaining sauce and sprinkle with the remaining cheeses. Bake until hot and bubbly, about 15 minutes. Cut into squares to serve. Makes four servings [ WEIGHT WATCHERS Magazine Low Calorie, Low Cost Menus ]