If you love lasagna but want to keep things low-carb, this Keto Zucchini Lasagna Casserole hits the spot. It’s layered with seasoned meat sauce, creamy ricotta, and plenty of gooey cheese—without the pasta. Zucchini stands in for noodles, keeping the dish light but still hearty and satisfying.
The flavors are classic, the prep is simple, and the leftovers are even better the next day. It’s an easy weeknight winner that feels like comfort food without the carb crash.
Keto Zucchini Lasagna Casserole - Comforting, Low-Carb, and Cheesy
Ingredients
- 3 medium zucchini, ends trimmed
- 1 pound ground beef (85–90% lean) or ground turkey
- 1 tablespoon olive oil (if needed for browning)
- 3 cloves garlic, minced
- 1 small yellow onion, finely diced (optional but tasty)
- 1 1/2 cups low-carb marinara sauce (no added sugar)
- 2 teaspoons Italian seasoning
- 1/2 teaspoon red pepper flakes (optional)
- Salt and black pepper, to taste
- 1 1/2 cups whole-milk ricotta cheese
- 1 large egg
- 1/2 cup grated Parmesan cheese, divided
- 2 cups shredded mozzarella cheese
- Fresh basil or parsley, chopped (for garnish)
Instructions
- Prep the zucchini. Use a mandoline or sharp knife to slice zucchini lengthwise into 1/8- to 1/4-inch planks. Lay slices on paper towels, sprinkle lightly with salt, and let sit 15 minutes to draw out moisture. Pat dry.
- Optional pre-bake for less moisture. Arrange zucchini slices on two parchment-lined sheet pans and bake at 400°F (200°C) for 8–10 minutes. This step helps prevent a watery casserole.
- Make the meat sauce. Heat a large skillet over medium-high. Add ground beef (and olive oil if needed). Cook, breaking it up, until browned. Add onion and cook 3 minutes, then stir in garlic for 30 seconds.
- Season and simmer. Stir in marinara, Italian seasoning, red pepper flakes, 1/2 teaspoon salt, and a few grinds of pepper. Reduce heat and simmer 5–8 minutes to thicken slightly. Taste and adjust seasoning.
- Mix the ricotta layer. In a bowl, combine ricotta, egg, 1/4 cup Parmesan, a pinch of salt, and pepper. Mix until smooth.
- Assemble. Lightly grease a 9x13-inch baking dish. Spread a thin layer of meat sauce on the bottom. Add a layer of zucchini slices, slightly overlapping. Dollop and gently spread half the ricotta mixture, then sprinkle with 1/3 of the mozzarella.
- Repeat layers. Add more meat sauce, another zucchini layer, the remaining ricotta, and another 1/3 of the mozzarella. Finish with remaining meat sauce, a final zucchini layer, and the rest of the mozzarella plus remaining 1/4 cup Parmesan.
- Bake. Cover loosely with foil (tent so cheese doesn’t stick) and bake at 375°F (190°C) for 25 minutes. Uncover and bake 12–15 more minutes, until bubbling and golden in spots.
- Rest and garnish. Let the casserole rest 10–15 minutes to set. Sprinkle with chopped basil or parsley before serving.
What Makes This Recipe So Good
- Real lasagna vibes, no pasta. Thinly sliced zucchini gives you that layered look and feel while staying keto-friendly.
- Bold, savory flavor. A rich meat sauce with garlic, Italian seasoning, and tomato gives it classic lasagna depth.
- Cheesy and satisfying. Ricotta, mozzarella, and Parmesan melt together for the perfect creamy, stretchy bite.
- Meal-prep friendly. Makes great leftovers and freezes well, so you can cook once and eat twice.
- Customizable. Easy to adapt for different proteins, extra veggies, or dairy preferences.
Ingredients
- 3 medium zucchini, ends trimmed
- 1 pound ground beef (85–90% lean) or ground turkey
- 1 tablespoon olive oil (if needed for browning)
- 3 cloves garlic, minced
- 1 small yellow onion, finely diced (optional but tasty)
- 1 1/2 cups low-carb marinara sauce (no added sugar)
- 2 teaspoons Italian seasoning
- 1/2 teaspoon red pepper flakes (optional)
- Salt and black pepper, to taste
- 1 1/2 cups whole-milk ricotta cheese
- 1 large egg
- 1/2 cup grated Parmesan cheese, divided
- 2 cups shredded mozzarella cheese
- Fresh basil or parsley, chopped (for garnish)
How to Make It
- Prep the zucchini. Use a mandoline or sharp knife to slice zucchini lengthwise into 1/8- to 1/4-inch planks. Lay slices on paper towels, sprinkle lightly with salt, and let sit 15 minutes to draw out moisture.
Pat dry.
- Optional pre-bake for less moisture. Arrange zucchini slices on two parchment-lined sheet pans and bake at 400°F (200°C) for 8–10 minutes. This step helps prevent a watery casserole.
- Make the meat sauce. Heat a large skillet over medium-high. Add ground beef (and olive oil if needed).
Cook, breaking it up, until browned. Add onion and cook 3 minutes, then stir in garlic for 30 seconds.
- Season and simmer. Stir in marinara, Italian seasoning, red pepper flakes, 1/2 teaspoon salt, and a few grinds of pepper. Reduce heat and simmer 5–8 minutes to thicken slightly.
Taste and adjust seasoning.
- Mix the ricotta layer. In a bowl, combine ricotta, egg, 1/4 cup Parmesan, a pinch of salt, and pepper. Mix until smooth.
- Assemble. Lightly grease a 9×13-inch baking dish. Spread a thin layer of meat sauce on the bottom.
Add a layer of zucchini slices, slightly overlapping. Dollop and gently spread half the ricotta mixture, then sprinkle with 1/3 of the mozzarella.
- Repeat layers. Add more meat sauce, another zucchini layer, the remaining ricotta, and another 1/3 of the mozzarella. Finish with remaining meat sauce, a final zucchini layer, and the rest of the mozzarella plus remaining 1/4 cup Parmesan.
- Bake. Cover loosely with foil (tent so cheese doesn’t stick) and bake at 375°F (190°C) for 25 minutes.
Uncover and bake 12–15 more minutes, until bubbling and golden in spots.
- Rest and garnish. Let the casserole rest 10–15 minutes to set. Sprinkle with chopped basil or parsley before serving.
How to Store
- Refrigerator: Cool completely, then cover tightly or portion into containers. Store up to 4 days.
- Freezer: Wrap individual portions or the whole casserole (baked and cooled) in a freezer-safe container.
Freeze up to 2 months. Thaw overnight in the fridge.
- Reheat: Oven at 325°F (165°C) for 15–20 minutes, or microwave in 60–90 second bursts until hot.
Health Benefits
- Low in carbs, big on satisfaction. Zucchini replaces pasta, keeping net carbs low while still delivering a hearty, layered meal.
- Protein-rich. Ground meat, ricotta, and mozzarella provide a solid protein base to keep you full longer.
- Nutrient-dense veggies. Zucchini offers fiber, potassium, and antioxidants with very few calories.
- Better fats. Using whole-milk cheeses supports satiety and helps with fat-soluble vitamin absorption, which fits a keto approach.
What Not to Do
- Don’t skip moisture control. Failing to salt and pat dry—or pre-bake—the zucchini can make the casserole watery.
- Don’t use a sugary sauce. Many marinara sauces have added sugar. Choose a low-carb brand and check the label.
- Don’t overwork the ricotta layer. Overmixing can make it runny.
Mix just until smooth and combined.
- Don’t cut too soon. If you slice right out of the oven, layers can slide. Resting helps it set.
Recipe Variations
- White lasagna style: Swap marinara for a keto-friendly Alfredo or creamy garlic Parmesan sauce, and add sautéed spinach or mushrooms.
- Spicy Italian: Use hot Italian sausage (casings removed) in place of ground beef and add extra red pepper flakes.
- Turkey and pesto: Use ground turkey and a mix of marinara and basil pesto for a bright, herby twist.
- Veggie-loaded: Add sautéed mushrooms, spinach, or bell peppers to the meat sauce. Drain well to avoid extra moisture.
- Dairy tweaks: Replace ricotta with cottage cheese (blended for smoothness) or use part-skim mozzarella if you prefer lighter dairy.
FAQ
How do I keep zucchini lasagna from being watery?
Pat the slices dry after salting, and pre-bake them for a few minutes to release moisture.
Also simmer the sauce until it’s slightly thickened, and let the casserole rest before slicing.
Can I make this ahead?
Yes. Assemble it up to 24 hours in advance, cover, and refrigerate. Bake straight from the fridge, adding 5–10 extra minutes.
Or bake fully, cool, and reheat when ready.
What’s the best marinara for keto?
Look for a sauce with no added sugar and 4–6 grams net carbs per 1/2 cup. Brands that list only tomatoes, olive oil, garlic, onion, and herbs are your safest bet.
Do I need the egg in the ricotta?
The egg helps bind the ricotta so the layers hold together. You can skip it, but the texture may be looser.
If skipping, reduce any extra liquid elsewhere.
Can I grill the zucchini instead?
Absolutely. Lightly oil the slices and grill 1–2 minutes per side to char and dry them slightly. This adds great flavor and helps reduce moisture.
What pan size works best?
A standard 9×13-inch dish fits the layers well.
If you prefer thicker layers, use a slightly smaller deep-dish casserole and add a few more minutes to the bake time.
Wrapping Up
This Keto Zucchini Lasagna Casserole brings all the comfort of classic lasagna without the carbs. It’s easy to prep, big on flavor, and flexible enough to match your taste. Keep a pan in the fridge for simple dinners all week—or freeze portions for future you.
When you want cozy, cheesy, and keto-friendly, this one delivers every time.