Ingredients:

  • 20 oz frozen chopped spinach, thawed and squeezed bone-dry
  • 15 oz whole milk ricotta cheese
  • 1 large egg, lightly beaten
  • 1 cup freshly grated Parmigiano-Reggiano
  • 0.5 tsp freshly grated nutmeg
  • 1 tsp sea salt, divided
  • 0.5 tsp cracked black pepper
  • 4 tbsp unsalted butter
  • 0.25 cup all-purpose flour
  • 3 cups whole milk, warmed
  • 2 cloves garlic, grated
  • 12 no-boil lasagna noodles
  • 4 cups low-moisture mozzarella cheese, shredded

Instructions:

  1. Prepare the spinach filling: In a large bowl, combine the bone-dry squeezed spinach with the ricotta, beaten egg, grated Parmigiano-Reggiano, nutmeg, and half the salt and pepper. Mix with a fork until the spinach is evenly distributed and no large clumps remain.
  2. Make the Béchamel sauce: In a heavy-bottomed saucepan, melt 4 tablespoons of butter over medium heat. Whisk in the flour and cook for 2 minutes until nutty but pale. Gradually whisk in the warmed milk and grated garlic. Simmer, stirring constantly, until the sauce thickens enough to coat the back of a spoon. Season with remaining salt.
  3. Assemble the lasagna: Spread a thin layer of Béchamel on the bottom of a 9x13 inch baking pan. Lay 3 to 4 no-boil noodles over the sauce. Spread a portion of the spinach-ricotta mixture over the noodles, followed by a layer of shredded mozzarella and more Béchamel.
  4. Repeat layers: Continue layering noodles, ricotta mixture, mozzarella, and Béchamel until all ingredients are used, ending with a generous layer of mozzarella on top.
  5. Bake: Cover the pan with foil and bake at 375°F (190°C) for 25 minutes. Remove foil and bake for another 15-20 minutes until the cheese is bubbly and has a deep mahogany-colored crust.
  6. Rest: Allow the lasagna to sit for 15 minutes before slicing to ensure the structural layers set properly.