Preheat your oven to 350°F or 175°C (350°F).
Cook the lasagna noodles according to package directions until al dente.
Drain them well, rinse with cold water to stop the cooking process, and lay them in a single layer on a sheet of foil to prevent sticking.
Prepare a 3-quart or 9x13-inch rectangular baking dish by lightly coating it with nonstick cooking spray.
In a large skillet coated with cooking spray, sauté the chopped leek over medium heat for about 4 minutes until it begins to soften.
Add the sliced zucchini, mushrooms, and roasted red peppers.
Continue to cook, stirring occasionally, for 8-10 minutes until the vegetables are tender and the excess moisture has evaporated.
Remove from the heat and stir in the fresh basil.
While the vegetables cook, create the creamy filling.
In a food processor or blender, combine the cottage cheese, eggs, and minced garlic.
Blend until the mixture is completely smooth and creamy.
Transfer to a bowl and stir in the thoroughly squeezed-dry spinach.
It's time to assemble! Start by placing 3 cooked noodles in the bottom of your prepared baking dish.
Top with half of the vegetable mixture, followed by one-third of the creamy spinach-cottage cheese filling.
Repeat these layers once more: 3 noodles, the remaining vegetable mixture, and another third of the cheese filling.
Finish with a final layer of 3 noodles, spread the last of the cheese filling on top, and sprinkle evenly with the shredded mozzarella. To prevent sticking, lightly spray a sheet of foil with cooking spray and cover the dish tightly.
Bake the covered lasagna for 45 minutes. Carefully remove the foil and bake for an additional 5 minutes, or until the cheese is bubbly and lightly golden.
Let the lasagna stand for 10 minutes before slicing—this is crucial for clean servings!
Sprinkle with fresh black pepper and garnish with shredded spinach, if desired, before serving.
Squeeze the thawed spinach *very* well. Use your hands, a potato ricer, or a clean kitchen towel to wring out as much water as possible. This is the key to preventing a watery lasagna.
