Spinach Lasagna
Pasta
Lasagna
12 uncooked lasagna noodles
1 pound whole-milk mozzarella cheese, shredded (4 cups), divided
Mornay Sauce
4 tablespoons unsalted butter
2 tablespoons minced garlic cloves (from 6 large cloves)
¼ cup all-purpose flour
4 cups whole milk
8 ounces Gruyère cheese, shredded (about 2 cups)
1 teaspoon kosher salt
⅛ teaspoon ground nutmeg
Spinach Ricotta
¼ cup olive oil
1 cup medium sweet onion, finely chopped (about 1 cup)
1 teaspoon kosher salt, divided
½ teaspoon black pepper, divided
3 (8-ounce) packages fresh baby spinach
1 (15-ounce) container whole-milk ricotta cheese
1 ounce Parmesan cheese, grated (1 cup)
1 large egg, beaten
Prepare the Spinach Ricotta
Heat oil in a large deep-sided skillet over medium-high.
Add onion, 1/2 teaspoon of the salt, and 1/4 teaspoon of the pepper; cook, stirring occasionally, until translucent, about 4 minutes.
Add spinach, a few handfuls at a time, and cook, stirring often, until all spinach is wilted, about 5 minutes.
Transfer to a mesh strainer, and press spinach to remove as much liquid as possible.
Set aside 1 1/2 cups spinach mixture. Transfer remaining 1 cup spinach mixture to a food processor; pulse until finely chopped, 8 to 10 pulses. Transfer finely chopped spinach to a large bowl.
Add ricotta, Parmesan, egg, and remaining 1/2 teaspoon salt and 1/4 teaspoon pepper; fold until well combined (makes 3 cups). Set aside.
Prepare the Mornay Sauce
Wipe large deep-sided skillet clean; add butter, and heat over medium.
Add garlic; cook, stirring occasionally, until fragrant, about 1 minute.
Add flour, and cook, stirring constantly, until roux is light golden, about 1 minute.
Gradually whisk in milk, and bring to a simmer over medium; simmer, stirring often, until sauce thickens enough to coat the back of a spoon, about 3 minutes.
Gradually whisk in Gruyère cheese until fully melted and smooth.
Remove from heat, and stir in salt and nutmeg.
Cook lasagna noodles according to package instructions in a large pot of boiling salted water, stirring occasionally, until al dente.
Drain noodles, and rinse under cold water. Dry noodles between layers of paper towels.
Preheat oven to 350°F.
Spread 3/4 cup Mornay Sauce in the bottom of a 13- x 9-inch metal pan or ceramic baking dish.
Top with 3 noodles. Spread 1 cup of Spinach Ricotta over the noodles; top with 1/2 cup of the reserved spinach mixture, 1 cup mozzarella, and 3/4 cup Mornay Sauce. Repeat the layering process 2 times.
Top with remaining 3 noodles, 1 cup Mornay Sauce, and 1 cup mozzarella.
Cover with aluminum foil coated with cooking spray to avoid the cheese sticking.
Bake for 30 minutes.
Remove foil, and continue bake until the lasagna is bubbling along edges and a crust starts to form on top, about 15 minutes.
Increase oven temperature to broil (do not remove lasagna from oven); broil until cheese is browned and bubbly, 3 to 5 minutes.
Remove from oven, and let stand 30 minutes before serving.