This dish is all about the sauce. It is chunky, flavorful and absolutely packed with veggies. Don't skimp on the cooking time. The combo of tomatoes plus time is a must, to allow the flavors to intensify.
Technique tip: The key to avoiding watery lasagna lies in the careful process of thinly slicing the zucchini and then removing the excess moisture.
For the veggie-full marinara:1.
In a large saucepan over medium heat, heat the olive oil and cook the onions, stirring, until translucent, about 5 minutes.2.
Add the garlic, carrot, zucchini and mushrooms, and cook, stirring, until the vegetables are soft and aromatic, about 5 more minutes. Stir in the oregano and thyme.3.
Add the canned tomatoes and cook, covered (but stirring occasionally), until very soft, about 20 minutes.4.
Whisk in the tomato paste and 3/4 cup water. Cook, uncovered, until the sauce is thickened, 15 more minutes. If you're making it for lasagna, continue to cook until it's almost spreadable, with very little liquid left, to maximize flavor.5.
Remove the sauce from the heat and use a hand blender to finish.6.
Stir in the fresh basil, and season with salt and pepper to taste.7.
Transfer the marinara to jars. It keeps for 2 days in the fridge, or you can freeze it for up to 2 months.
For the lasagna:1.
Using a mandolin or a sharp chef's knife, slice the zucchini lengthwise into 1/8-inch-thick strips. Sprinkle the strips with salt and lay them on paper towels, with two more layers of towels on top to absorb the moisture they expel. Let them sit for 30 minutes, pressing down on the towels occasionally to squeeze out excess moisture.2.
Preheat the oven to 350°F.3.
Line the bottom of the lasagna pan with a single layer of zucchini strips, overlapping the edges for complete coverage.4.
Top the zucchini with a thin layer of mozzarella cheese (about 1/4 of the total mozzarella) followed by a layer of the marinara.5.
Repeat the layers-zucchini noodles, cheese, and then sauce-to make a total of 3 complete layers.6.
Top the final layer of marinara sauce with the remaining mozzarella and the Parmesan.7.
Bake, uncovered, for 40 minutes, or until the lasagna bubbles. During the last 10 minutes of cooking raise the oven temperature to 400°F to brown the cheese. Serve. Keeps for 2 days in the fridge.