As posted on Boston.com
Serves 8

You need to roast asparagus, cook mushrooms, then spinach, make a white sauce, and a ricotta mixture. The lasagna noodles go into the dish without preliminary cooking, so you’ll need to bake it over an hour. Allow enough time. The end result is stunning and delicious.
Ingredients:

• 3 bunches asparagus, ends snapped off (about 2 1/2 pounds)


• 6 tablespoons olive oil


• 2 medium onions, coarsely chopped


• Salt and pepper, to taste


• 10 ounces mushrooms, sliced


• 10 ounces fresh spinach, stems trimmed


• 2 pounds fresh ricotta


• 2 eggs


• 1/2 cup grated Parmesan


• 1/2 cup (1 stick) butter


• 1/2 cup flour


• 3 cups milk


• 1/2 box ( 1/2 pound) lasagna noodles


• 8 ounces shredded mozzarella
  1. Set the oven at 400 degrees. Have on hand a deep 9-by-13-inch baking dish. Cut off the asparagus tips; reserve for the top. Cut the remaining spears into 1/2-inch pieces. In the baking dish, toss the asparagus spears and 1 tablespoon of the oil. Roast for 20 minutes or until tender. Remove from the dish.
  2. Turn the oven temperature down to 350 degrees.
  3. In a large skillet over medium heat, heat 2 tablespoons of the olive oil. Add the onions, salt, and pepper. Cook, stirring often, for 5 minutes. Add the mushrooms and continue cooking, stirring often, for 5 minutes or until they release their juices. Turn up the heat and cook, stirring, until the juices evaporate.
  4. Remove the mixture from the skillet. Wipe it out. Add 2 tablespoons of the oil. Cook the spinach, stirring constantly, for 2 minutes or until it wilts. Add salt and pepper.
  5. With tongs, transfer the spinach to a board, leaving any liquid in the pan. Let the spinach cool. Chop it coarsely. Transfer to a bowl. Add the ricotta, eggs, Parmesan, salt, and pepper.
  6. Wipe out the skillet. Add the butter and when it melts, whisk in the flour. Cook, whisking constantly, for 2 minutes. Gradually whisk in the milk. When it comes to a boil, add salt and pepper, lower the heat, and simmer, whisking often, for 2 minutes.
  7. Spread enough white sauce in the baking dish to make a thin layer. Add enough sheets of lasagna to cover the bottom, breaking them if necessary to fit. Dot with 1/3 of the sauce, 1/2 of the ricotta, 1/2 of the mushroom mixture, 1/2 of the roasted asparagus, and 1/3 of the mozzarella.
  8. Add another layer of lasagna to cover the filling, 1/3 of the sauce, the remaining ricotta, remaining mushroom mixture, remaining roasted asparagus, and 1/3 of the mozzarella.
  9. Add another layer of lasagna to cover the filling, spread with remaining sauce, and sprinkle with remaining mozzarella. Toss asparagus tips with remaining 1 tablespoon olive oil. Set on top.
  10. Cover with foil. Set the dish on a rimmed baking sheet. Bake for 70 minutes, or until the pasta is tender when pierced with a skewer.
  11. Turn the oven temperature to 425 degrees. Uncover the lasagna and continue baking for 10 minutes or until the top is brown.
  Adapted from Verrill Farm