Step 1

Preheat the oven to 450 degrees Fahrenheit.

Step 2

Mince the garlic. Add the butter to a medium saucepan over medium heat: once melted, add the garlic and saute until fragrant, about 1 minute. Turn down the heat and carefully add the crushed tomatoes, tomato sauce, basil, tarragon, 1/2 teaspoon kosher salt, and several grinds of black pepper. Remove 1/4 cup of the sauce and stir it with the cornstarch, then add it back to the pan (this helps to thicken the sauce). Simmer while making the remainder of the recipe, at least 15 minutes. When ready to use, remove the pan from the heat.

Step 3

Slice the zucchini into noodles 1/4 inch thick, using a knife or mandoline (if you have a mandoline, it’s the easiest way to get uniform pieces). You can discard the pieces that are just the peel. Place the zucchini strips on two parchment-lined baking sheets and drizzle them with olive oil, then use your hands to rub it so they are lightly coated on both sides. Sprinkle with 1 teaspoon kosher salt, divided across the 2 trays. Roast 10 to 12 minutes, until just tender. Remove the pans from the oven and set aside.

Step 4

Destem the thyme, then roughly chop the leaves. Add 2 tablespoons thyme to a medium bowl and reserve about 1/2 tablespoon for topping the lasagna. To the bowl, add the lemon zest, ricotta cheese, 1/2 cup Parmesan cheese, 1 cup shredded mozzarella cheese, nutmeg, 1/2 teaspoon kosher salt, and several grinds of black pepper. Stir to combine.

Step 5

Turn down the heat to 375 degrees Fahrenheit.

Step 6

In a 9” x 9” baking dish (or similar volume baking dish), spread a 1/2 cup tomato sauce on the bottom of the pan. Then top with 1 layer of the zucchini noodles, half of the cheese mixture (in dollops) and about 1/2 cup of the tomato sauce, using a spatula to spread the sauce evenly over the cheese. Repeat again, topping with 1 layer of noodles, the remaining cheese mixture, and 1/2 cup of the remaining tomato sauce. Finally, top with a final layer of noodles, then another 1/2 cup tomato sauce. Sprinkle the entire top with the remaining 1 cup mozzarella cheese, 1/4 cup Parmesan cheese, and 1/2 tablespoon fresh thyme.

Step 7

Bake the lasagna for 40 minutes, uncovered. Let stand for at least 15 minutes before serving (this allows the lasagna to set; you can let it sit even longer if desired). Leftovers can be refrigerated for 2 to 3 days and reheated in a 375°F oven.