Cheesy Zucchini Casserole

Prep: 15 minutes
Bake: 30–35 minutes
Total: 45–50 minutes
Servings: 6

Ingredients

Zucchini mixture

4 medium zucchini, thinly sliced — about 700–800 g
1 small onion, finely diced
2 cloves garlic, minced
1 tbsp olive oil
½ tsp salt
½ tsp black pepper
½ tsp Italian seasoning
¼ tsp paprika

Creamy cheese layer

½ cup heavy cream
2 large eggs
½ cup sour cream
1 cup shredded mozzarella
½ cup grated Parmesan
½ cup shredded cheddar or Monterey Jack

Topping

½ cup breadcrumbs or panko
2 tbsp grated Parmesan
1 tbsp melted butter
2 tbsp chopped fresh parsley

Instructions

Preheat oven: Set oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish.
Prepare zucchini: Slice zucchini into thin, even rounds. Sprinkle lightly with salt and let sit for 10 minutes. Pat dry with paper towels to remove excess moisture.
Cook aromatics: Heat olive oil in a skillet over medium heat. Add onion and cook for 3–4 minutes. Add garlic and cook for another 30 seconds.
Make cheese mixture: Whisk together heavy cream, eggs, and sour cream. Stir in mozzarella, Parmesan, cheddar, Italian seasoning, black pepper, and paprika.
Combine: Add zucchini and sautéed onion mixture to the cheese mixture. Toss gently until well coated.
Layer: Transfer everything to the prepared baking dish and spread evenly.
Make topping: Combine breadcrumbs, 2 tbsp Parmesan, and melted butter. Sprinkle evenly over the casserole.
Bake: Bake uncovered for 30–35 minutes, until bubbling and golden brown on top.
Brown the top: For extra color, broil for 1–2 minutes, watching closely.
Rest: Let stand for 5–10 minutes before serving. Finish with fresh parsley.

Nutrition — Approx. per serving

Based on 6 servings; actual values vary with brands and exact quantities.

Nutrient	Amount
Calories	~390 kcal
Protein	~18 g
Carbohydrates	~17 g
Fiber	~3 g
Net carbs	~14 g
Total fat	~29 g
Saturated fat	~16 g
Cholesterol	~130 mg
Sodium	~650 mg
Sugar	~6 g
Calcium	~390 mg
Potassium	~600 mg

Nutrition notes

Zucchini: provides fiber, potassium, vitamin C, and antioxidants.
Cheese: adds substantial protein and calcium but also increases saturated fat and sodium.
Eggs: contribute protein and choline.
Breadcrumbs: add carbohydrates and calories; use whole-wheat breadcrumbs for more fiber.
For a lower-calorie version, replace half the heavy cream with milk and reduce the cheese slightly.
For a low-carb/keto version, replace breadcrumbs with crushed pork rinds or almond flour.

Quick Q&A

Can I make it ahead?
Yes. Assemble it, cover, and refrigerate for up to 24 hours. Add about 5–10 minutes to the baking time if starting cold.

Why is my casserole watery?
Zucchini releases a lot of water. Salting, drying, and briefly sautéing the zucchini helps prevent this.

Can I use frozen zucchini?
Yes, but thaw and squeeze it very thoroughly before using.

Can I add chicken?
Yes. Add about 2 cups of cooked shredded chicken for a more substantial meal.

Can I make it without breadcrumbs?
Absolutely. Simply omit them and use extra Parmesan for a cheesy crust.

How do I store leftovers?
Refrigerate in an airtight container for 3–4 days. Reheat in the oven or air fryer for the best texture.

Author
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Sara Mitchell

Sara Mitchell is an expert restaurant content creator who writes easy-to-read guides about CAVA and other Mediterranean fast-casual chains in the United States. She covers locations, menus, prices, and hours, making it simple for visitors to find nearby restaurants and what to order quickly.

With years of experience in restaurant research and local SEO, Sara creates accurate, user-friendly guides that work for both people and search engines. Her goal is to help users go from search results to their nearest restaurant or menu choice with as few clicks as possible.