Zucchini Lasagna (Keto & GF)

by Kendall
4 pieces
1 hr

· Print Recipe

A comfort food classic that won’t leave you bloated or sluggish, this Zucchini Lasagna is sure to become a staple in your home! Made from simple, wholesome ingredients that are keto, gluten-free and vegetarian, it’s a delicious and nutritious meal the whole family can enjoy. I promise no one will even miss the noodles!

Recipe includes instructions for ensuring your zucchini lasagna comes out firm and not watery, as well as modifications for different dietary preferences.

How to Make Zucchini Lasagna

Don’t be intimidated by the lengthy ingredients list or the fact that this lasagna takes an hour to make from start to finish. It’s actually incredibly easy and the prep time is only about 20-25 minutes.

You’ll prepare each part of the lasagna separately, but can save time by doing some of it concurrently. While the sliced zucchini rest (more on that later!), prepare your red sauce by sautéing the veggies and reducing the tomatoes. While that simmers, you can prepare your ricotta cheese filling by whisking together all the ingredients in a small bowl.

Once all parts of your lasagna are ready – zucchini noodles, red sauce, ricotta filling and mozzarella – it’s time to assemble the dish in layers.

Start with about 1/4 cup of red sauce on the bottom of an 8×8 or 9×9 pan and place four zucchini noodles on top, as pictured. Cover each slice of zucchini with the ricotta filling, followed by a layer of shredded mozzarella. Finally, cover the mozzarella in more tomato sauce and repeat the layering process. As written, the recipe will make four or five layers. End the final layer with mozzarella cheese.

How do you slice zucchini lengthwise for lasagna?

To achieve perfectly sliced zucchini noodles for lasagna, use a mandoline slicer and set the blade to 1/8″ thickness. Cut the ends off of each zucchini and run them through the slicer lengthwise. Be extra careful not to get your fingers too close to the blade!

The first and last two slices of a zucchini won’t be very wide. Because of this, I tend not to use these pieces in the lasagna. Instead, I only use the slices from the middle of the zucchini. This ensures each “noodle” in the dish is about the same length and width.

How to make Zucchini Lasagna Not Watery

The biggest challenge with veggie lasagna is making sure it stays firm and doesn’t become too watery while it’s cooking. Most vegetables that are used to replace pasta contain a lot of water. This moisture seeps out into a dish as the vegetables cook and can leave you with a soupy consistency. Not nice at all!

To prevent that from happening to your lasagna, spread the sliced zucchini out on a cutting board or tray, as pictured. Sprinkle each slice with salt and leave them to sit for at least 15 minutes. The salt will pull out a lot of moisture from the zucchini, which would have otherwise ended up in your lasagna. After 15 minutes, pat the zucchini dry with paper towels, flipping each slice to dry the underside as well.

Modifications and Substititions

As written, this recipe is vegetarian. If you eat meat, feel free to add anywhere from half a pound to a full pound of ground beef to the sauce. Add the beef after step 4 and cook until no longer pink before continuing to step 5.

While I prefer zucchini noodles as my pasta substitute, other vegetables would work with this recipe as well. Try using sweet potatoes (if not following a keto diet) or eggplants with the mandoline slicer for a variation on this veggie lasagna. If you use sweet potatoes, you can skip the salting step. Sweet potatoes don’t contain as much water as zucchini and won’t result in a watery lasagna.

Can I freeze vegetable lasagna?

Since you took the time to pull the excess water out of the zucchini, this veggie lasagna is actually a great candidate for freezing!

I recommend cutting the zucchini lasagna up into single servings and freezing them individually. Wrap each piece in plastic wrap and/or tinfoil, or simply place the pieces in a freezer-safe container. If you’re using a container, be sure there is space between each piece, otherwise they’ll freeze together.

To thaw, remove the number of pieces you want to serve from the freezer and leave them in the fridge overnight. Reheat in the microwave or in the oven.

Looking for other keto and gluten-free dinner ideas? Try some of my most popular recipes:

  • Best Cauliflower Pizza Crus t
  • Zucchini Noodle Shrimp Scampi
  • Vegan Meatballs (Keto & GF)

If you make this Zucchini Lasagna, please rate it and add your comments below. And be sure to tag @thebespokebites in your photos and videos on Instagram for a chance to be featured!

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Zucchini Lasagna (Keto & GF)
Recipe details
  • 4  pieces
  • Prep time: 25 Minutes Cook time: 35 Minutes Total time: 1 hr
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  • 2–3 medium zucchini
  • 2 tablespoons olive oil
  • 2 cloves garlic, minced
  • 1/2 cup diced red onion (about half an onion)
  • 1 can (28oz) crushed tomatoes
  • 3 tablespoons tomato paste
  • 1/2 teaspoon oregano
  • 1/2 teaspoon thyme
  • 1/4 teaspoon salt
  • 1/2 cup ricotta cheese
  • 1/2 cup freshly grated Parmesan cheese
  • 1 egg, beaten
  • 1/4 cup freshly chopped basil
  • 1/4 teaspoon salt
  • 1/8 teaspoon pepper
  • 2 cups shredded mozzarella cheese

Preheat oven to 400.
Using a mandoline slicer, slice zucchini lengthwise. I aim for about 1/8 of an inch thick slices. Slice enough zucchini so that you end up with 16-20 evenly sized pieces.
Lie the slices of zucchini flat on a tray or cutting board and season generously with salt. Leave them to sit for 15 minutes. The salt will pull out some of the moisture from the zucchini and prevent the lasagna from coming out too watery.
While the salted zucchini sits for 15 minutes, prepare the sauce by heating the olive oil in a large skillet on the stove at medium-high heat. Add the garlic and onion and sauté until the onion is translucent; about 3 minutes.
Stir in the can of crushed tomatoes, tomato paste, oregano, thyme and salt. Bring to a slight boil, stirring constantly, for 2 minutes. Reduce heat to low and let the sauce simmer.
While the sauce simmers, prepare the cheese filling by mixing the ricotta, parmesan cheese, egg, basil, salt and pepper in a small bowl. Set aside.
After the zucchini has sat for 15 minutes, pat each piece dry with paper towels. Flip the pieces and pat again, being sure to remove as much water as possible.
Spread 1/4 cup of the tomato sauce along the bottom of a 9×9 casserole dish. Add four slices of zucchini side-by-side on top of the sauce. Add about 1/4 cup of the ricotta mixture on top of the zucchini noodles and spread evenly. Add 1/2 cup of shredded mozzarella cheese on top of the ricotta.
Add enough tomato sauce to evenly cover the mozzarella cheese and continue to layer the lasagna with zucchini noodles, ricotta cheese, and mozzarella cheese as explained in step 8. The recipe will make 4 or 5 layers. For the final layer, top with mozzarella cheese and some freshly chopped basil.
Place the casserole dish in the oven and bake for 35 minutes or until the top layer of mozzarella is bubbling and browning.
Remove from the oven and let stand for 10 minutes. Garnish with fresh basil and serve!
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