Winter Greens and Walnut Lasagna

FILLING
- 3 pounds assorted winter greens, such as chard, escarole, and kale
- 2 tablespoons olive oil
- 1 large onion, chopped
- 2 garlic cloves, finely chopped
- Salt and freshly ground black pepper
- 3 cups whole-milk ricotta
- 1 cup toasted and coarsely chopped walnuts
- ½ cup (2 ounces) freshly grated Parmesan
- 3 large eggs, beaten
- 3 tablespoons finely chopped fresh parsley
- ¼ teaspoon freshly grated nutmeg
- 3 tablespoons unsalted butter
- 3 tablespoons all-purpose flour
- 1½ cups whole milk, heated
- ½ cup (2 ounces) freshly grated Parmesan
- Salt and freshly ground black pepper
- 1 pound dried lasagna
- 4 cups (1 pound) shredded mozzarella
- ½ cup (2 ounces) freshly grated Parmesan
- 2 tablespoons butter, cut into small cubes, plus more for the dish
Instructions:
Like most lasagna dishes, it isn’t quick to make, but the return on your time investment is very high.
- To make the filling, remove the tough stems from the greens. Chop the stems into ½-inch-thick pieces. Fill a sink with cold water and add the stems. Wash the stems well. Lift out of the water and set aside in a bowl; do not dry. Fill the sink with fresh water. A few at a time, stack the leaves and cut crosswise into ½-inch-wide strips. Add to the water and wash well. Lift out of the water and transfer to a large colander; do not dry.
- Heat the oil in a large saucepan over medium heat. Add the onion and cook, stirring occasionally, until golden, about 5 minutes. Stir in the garlic and cook until fragrant, about 1 minute. Add the stems and cover. Cook until the stems are crisp-tender, about 5 minutes. Stir in the greens, season with salt and pepper, and cover. Cook until the leaves are very tender, about 15 minutes. Drain in a colander and let cool until easy to handle.
- A handful at a time, squeeze the excess liquid from the greens, and place the greens in a large bowl. Add the ricotta, walnuts, Parmesan, eggs, parsley, 1½ teaspoons salt, ½ teaspoon pepper, and the nutmeg. Mix well.
- To make the sauce, melt the butter in a medium saucepan over medium-low heat. Whisk in the flour and let the roux bubble without browning for 1 minute. Whisk in the hot milk and increase the heat to medium. Cook, whisking often, until the sauce is boiling and thickened. Remove from the heat. Stir in the Parmesan and season with salt and pepper to taste. Cover and set aside.
- Meanwhile, bring a large pot of salted water to a boil over high heat. Stir in the lasagna and cook according to the package directions until al dente. Drain and rinse under cold running water.
- Lightly butter a 13 x 9-inch baking dish. Spread about 3 tablespoons of the sauce in the bottom of the dish. Layer 4 lasagna noodles, slightly overlapping, in the dish. Spread with one-third of the filling and sprinkle with one-third of the mozzarella. Repeat with two more layers of the noodles, filling, and mozzarella. Top with a final layer of noodles (you will have some left over). Spread with the remaining sauce, sprinkle with the Parmesan, and dot with the butter. (The lasagna can be prepared up to 1 day ahead, cooled, covered, and refrigerated.)
- Position a rack in the center of the oven and preheat to 350°F. Place the baking dish on a rimmed baking sheet. Bake until the sauce is bubbling and tinged with golden brown, 40 to 45 minutes. Let stand for 10 minutes, then serve hot.