My mom's Spinach Pie is the greatest start for this recipe because you already bring two key ingredients to the lasagna — mozzarella and ricotta cheeses, as well as the flavor of garlic. Yes, I have added more cheese here, but that's more for making the layers all hold together nicely and to add to the awesome gooey strings that follow your spatula after removing a slice. The spinach offsets the richness nicely and I love the spicy, savory kick of the Italian sausage. Buon appetito!
Technique tip: Start with baking dish covered loosely with foil in the oven, then uncover for the last 10-15 minutes to let cheese brown for the remainder of time. Drain the oil from the sausage before adding.
Swap option: Many companies make oven-ready lasagna sheets. Using these can save you prep time when you are trying to get a meal on the table faster.
Preheat oven to 350 F. Grease a large glass or ceramic 11- by 17-inch baking dish with about 1/2 tablespoon of olive oil.2.
In a medium saucepan over medium-low heat, heat 1 tablespoon of olive oil. Add the diced onion and a large pinch of salt. Sauté until the onion is translucent, about 3 minutes.3.
Add the minced garlic and combine with onion.4.
Add sausage, breaking up larger clumps of meat so all is evenly browned.5.
When sausage begins to brown, add red pepper flakes and stir to combine.6.
When sausage mixture is browned (watch carefully to ensure it does not burn), remove from heat, drain off oil and set aside in medium bowl.7.
Boil roughly 5 quarts of water with 1 tablespoon of salt. When water boils, add noodles. Let come to boil again, and remove noodles when still somewhat al dente. Set aside.8.
Pour a thin layer of sauce to cover the bottom of the pan and roughly a 1/2-inch up the sides. This will keep your lasagna from sticking.9.
Place a layer of lasagna sheets side by side and line the bottom of the pan.10.
Spoon on a thin layer of sauce.11.
Top with the "playing card" rectangular slices of spinach pie. Cover the sheets end to end.12.
Spoon a thin layer of sausage mixture atop spinach mixture.13.
Sprinkle on a thin layer of shredded mozzarella.14.
Top with a second layer of lasagna sheets.15.
Repeat steps 10-13 until just about even with edge of pan; do not overfill.16.
Top the topmost layer with all the remaining cheese.17.
Cover loosely with aluminum foil and bake for 1 hour. If you uncover for the last 15 minutes, the lasagna will be a beautiful golden-brown.