Preheat your oven to 375°F and lightly grease a 9x13 baking dish with oil or cooking spray to prevent sticking during baking. Make sure the corners and sides are coated well because melted cheese can stick once baked. Set the dish aside while you prepare the rest of the ingredients.

Wash the zucchini thoroughly and trim the ends. Using a sharp knife or mandoline slicer, carefully slice the zucchini lengthwise into thin strips that resemble lasagna noodles. Try to keep the slices relatively even in thickness so they cook consistently and layer neatly inside the dish.

Lay the zucchini strips out on paper towels or a clean kitchen towel and sprinkle them lightly with salt. Let them sit for about 15–20 minutes. During this time, the salt helps draw out excess moisture from the zucchini, which is one of the most important steps for preventing watery keto lasagna.

After the zucchini has rested, gently pat all the slices dry using additional paper towels. Press lightly to remove as much surface moisture as possible without tearing the strips. The drier the zucchini, the firmer and more structured your lasagna will be after baking.

Heat a large skillet over medium heat and add the ground beef along with the diced onion. Break the beef apart using a spoon or spatula while it cooks. Continue cooking until the beef is fully browned and the onions become soft, translucent, and fragrant. This step builds the rich savory flavor base of the lasagna.

Add the minced garlic into the skillet and cook for about 1 additional minute, stirring frequently so the garlic doesn’t burn. The garlic should become fragrant and blend into the meat mixture beautifully.

Pour the sugar-free marinara sauce into the skillet and season with Italian seasoning, salt, and black pepper. Stir everything thoroughly until evenly combined. Allow the sauce to simmer gently for 10–15 minutes so it thickens slightly and develops deeper flavor. A thicker sauce helps the lasagna hold together better during slicing.

In a medium mixing bowl, combine the ricotta cheese, egg, and parmesan cheese. Stir until the mixture becomes smooth, creamy, and fully blended. This cheesy layer creates the rich creamy texture that makes lasagna feel comforting and indulgent.

Spread a thin layer of the meat sauce across the bottom of the prepared baking dish. This prevents the zucchini from sticking and creates a flavorful base for the first layer.

Arrange a layer of zucchini slices over the sauce, slightly overlapping the strips to create a noodle-like layer. Don’t worry if they aren’t perfectly lined up — once baked, everything settles together beautifully.

Spread part of the ricotta mixture gently over the zucchini layer using the back of a spoon or spatula. Sprinkle a generous amount of mozzarella cheese over the top for that classic gooey lasagna texture.

Continue layering the ingredients in the same order: meat sauce, zucchini slices, ricotta mixture, and mozzarella cheese. Repeat until all ingredients are used, finishing with a thick layer of mozzarella cheese on top for a golden bubbly finish.

Cover the baking dish loosely with aluminum foil and place it into the oven. Bake for approximately 30 minutes. Covering the lasagna during the first stage helps the inside cook evenly without overbrowning the cheese too early.

Carefully remove the foil and continue baking for another 15–20 minutes until the cheese becomes melted, bubbly, golden brown, and slightly crispy around the edges. The kitchen will smell incredible at this stage.

Remove the lasagna from the oven and allow it to rest for at least 15 minutes before slicing. This resting time is extremely important because it helps the layers firm up properly and makes slicing much cleaner and easier.

Slice the lasagna carefully using a sharp spatula or knife and serve warm with fresh basil, extra parmesan cheese, or your favorite keto-friendly side dishes like Caesar salad, roasted vegetables, or garlic butter green beans.