Polenta Lasagna with Butternut Squash and Spinach
Golden layers of polenta take the place of noodles in this colorful meatless lasagna, full of bright vegetables and creamy cheeses. Use stone-ground polenta to get the most nutritional benefit from the corn. Unlike most polenta, it retains some of the wholesome germ. Jarred marinara sauce can be used in place of the tomato sauce.
For the polenta:
- Olive oil for greasing
- 8 cups water
- 2 cups stone-ground polenta
- 1/2 tsp. salt
For the tomato sauce:
- 1 Tbs. extra-virgin olive oil
- 1 garlic clove, crushed
- 1 1/2 lb. ripe plum tomatoes, peeled and seeded, or 2 cups canned tomatoes with juice
- 2 Tbs. dry white wine or vermouth
- 1/2 tsp. salt
- Freshly ground pepper, to taste
- 1 Tbs. shredded fresh basil
- 6 cups peeled and diced butternut squash (about 2 lb.)
- 2 Tbs. olive oil
- 1/2 tsp. dried thyme
- 1/4 tsp. salt
- 1/8 tsp. freshly ground pepper
- 3 cups water
- 12 oz. spinach leaves (from about 1 lb. spinach)
- 2 cups part-skim ricotta cheese
- 1/8 tsp. freshly grated nutmeg
- 2 cups shredded mozzarella cheese
To make the polenta, lightly grease a 9-by-13-inch baking dish with olive oil. In a large, heavy-bottomed pot, bring the water to a boil over high heat. Pouring slowly and stirring constantly with a whisk, add the polenta and salt. Reduce the heat to medium-low and cook uncovered, stirring occasionally, until the mixture is thick and the texture is no longer grainy, about 25 minutes. Pour the polenta into the prepared dish and refrigerate until set, about 2 hours.
Meanwhile, make the tomato sauce: In a large fry pan over medium-high heat, warm the olive oil. Add the garlic and sauté until golden, 1 to 2 minutes. Add the tomatoes with their juices and crush them with a wooden spoon. Bring the mixture to a boil, then reduce the heat to medium. Add the wine, salt and a pinch of pepper and simmer for 15 minutes. Remove from the heat and let stand for 5 minutes. Discard the garlic. Puree in a food processor. Add the basil just before using. You will need 3 1/2 cups of the sauce for this recipe; refrigerate any remaining sauce for another use.
Preheat an oven to 400°F.
In a large baking pan, toss the butternut squash with the olive oil, thyme, salt and pepper. Roast until very tender, about 35 minutes. Transfer to a bowl and mash coarsely with a fork. Reduce the oven temperature to 350°F.
In a large pot over high heat, bring the water to a boil. Add the spinach and cook until just wilted, 1 to 2 minutes. Drain and rinse in cold water. Squeeze dry and coarsely chop. In a bowl, combine the spinach, ricotta, nutmeg and 1/2 cup of the mozzarella and stir well.
Cut the polenta crosswise into thirds and slice each piece in half horizontally. Spoon about 1/2 cup of the tomato sauce into a 9-by-13-inch baking dish. Arrange half of the polenta pieces in the pan, then spoon the mashed squash evenly over the polenta. Spoon half of the cheese mixture evenly over the squash and top with about 1 1/2 cups of the tomato sauce. Top with the remaining polenta pieces, then the remaining cheese mixture, remaining tomato sauce and remaining mozzarella.
Bake until the sauce is bubbling and the cheese is melted and golden, about 30 minutes. Let stand for 10 minutes before serving. Serves 8 to 10.
Adapted from Williams-Sonoma Eat Well, by Charity Ferreira (Oxmoor House, 2008).