Garlic Parmesan Zucchini Casserole Recipe
When you’re looking for a side dish that’s both healthy and full of flavor, Garlic Parmesan Zucchini Casserole is a fantastic option. Zucchini is a versatile vegetable that’s not only low in calories but also loaded with nutrients, including vitamins A, C, and several antioxidants. When paired with garlic, Parmesan cheese, and a few other simple ingredients, zucchini transforms into a savory casserole that everyone will love.
This recipe is perfect for those who are looking to get more vegetables into their meals, whether it’s for a weeknight dinner or a holiday gathering. It’s also a great way to use up the abundance of zucchini that often appears in gardens during the summer months. The best part? It’s incredibly easy to prepare and can be made ahead of time. The zucchini retains its moisture while the garlic and Parmesan provide layers of rich, aromatic flavors.
Step-by-Step Instructions for Garlic Parmesan Zucchini Casserole
Step 1: Prepare the Zucchini
Start by washing and drying your zucchini thoroughly. Since zucchini has a high water content, you want to slice it evenly to ensure it cooks properly. Cut the zucchini into 1/4-inch thick slices. If the zucchini is particularly large, you may want to cut it in half lengthwise before slicing to make smaller, more manageable pieces.
Once your zucchini is sliced, it’s a good idea to sprinkle a little salt on the slices and let them sit for about 10 minutes. This helps to draw out some of the excess water from the zucchini, which prevents the casserole from becoming too watery. After the 10 minutes, use a paper towel or clean kitchen towel to pat the zucchini slices dry.
Step 2: Sauté the Aromatics
In a large skillet or pan, heat 1 tablespoon of olive oil over medium heat. Add the minced garlic and chopped onion to the pan. Sauté for about 2-3 minutes until the garlic becomes fragrant and the onion softens. Be careful not to let the garlic burn, as it can turn bitter quickly.
If you’re using crushed red pepper flakes, add them in at this stage to infuse the oil with a little heat. The aromatic combination of garlic and onion will give the casserole a great flavor base.
Step 3: Combine the Cream and Cheese Mixture
While the garlic and onion are sautéing, grab a medium-sized mixing bowl and combine the following:
- Heavy cream (or half-and-half for a lighter option)
- Grated Parmesan cheese
- Shredded mozzarella cheese (if using)
- Fresh basil (or dried basil if using dried)
- Ground black pepper
- Salt
Whisk the ingredients together until they form a smooth mixture. This creamy mixture will be the binder that brings all the flavors together and coats the zucchini slices.
Step 4: Assemble the Casserole
Now that the zucchini is prepared and the cream mixture is ready, it’s time to assemble the casserole.
- Preheat your oven to 375°F (190°C).
- Grease a 9×13-inch casserole dish with butter to prevent the casserole from sticking. Alternatively, you can use non-stick cooking spray.
- Layer the sliced zucchini evenly across the bottom of the casserole dish. Depending on the size of your zucchini, this may take two to three layers.
- Pour the creamy Parmesan mixture evenly over the zucchini. Use a spoon or spatula to spread it out and ensure all the zucchini is covered in the creamy sauce.
Step 5: Add the Topping
To finish off the casserole, you’ll want to create a crispy topping. In a small bowl, mix the breadcrumbs with the remaining 1/4 cup of grated Parmesan cheese. Sprinkle this mixture evenly over the top of the casserole. This will create a nice, golden crust as it bakes in the oven.
Step 6: Bake the Casserole
Place the casserole dish in the preheated oven and bake for 25-30 minutes. The casserole is done when the top is golden brown and the zucchini is tender. If you like your topping extra crispy, you can broil the casserole for an additional 2-3 minutes at the end, but keep a close eye on it to prevent burning.
Once it’s done baking, remove the casserole from the oven and let it sit for about 5 minutes before serving. This allows the flavors to meld and makes it easier to cut into portions.
Serving Suggestions
This Garlic Parmesan Zucchini Casserole pairs beautifully with a variety of dishes. Here are some serving suggestions:
- As a Side Dish: This casserole is a perfect side dish for grilled chicken, baked salmon, or roasted pork. The creamy, cheesy flavor complements meats wonderfully, making it ideal for a balanced meal.
- With Pasta: Serve this casserole alongside or on top of a plate of pasta. Its rich, garlicky flavor would go great with spaghetti, fettuccine, or even zucchini noodles (for a low-carb twist!).
- With a Salad: Pairing the casserole with a fresh, crisp green salad can help balance out the richness of the dish. A simple Caesar salad or mixed greens with a lemon vinaigrette would be a great option.
- As a Vegetarian Main Course: If you want to keep things vegetarian, you can serve the casserole as the main dish, accompanied by a side of whole-grain bread or a small portion of quinoa for extra fiber.
Nutritional Benefits of Garlic Parmesan Zucchini Casserole
Zucchini is a low-calorie, nutrient-dense vegetable that provides a variety of health benefits. Here’s why this casserole is a great choice for your meals:
- Rich in Nutrients: Zucchini is a good source of vitamins C and A, both of which support immune health and promote healthy skin. It’s also high in potassium, which helps regulate blood pressure.
- High in Fiber: Zucchini provides a decent amount of fiber, which is essential for digestion and maintaining healthy blood sugar levels.
- Healthy Fats: The Parmesan cheese and olive oil in this recipe provide healthy fats that can support heart health and keep you feeling full longer.
- Low-Carb Option: If you’re following a low-carb or keto diet, this casserole is an excellent option. It’s naturally low in carbs, and the creamy, cheesy texture provides all the satisfaction without the extra carbohydrates from traditional pasta or rice dishes.
- Protein Boost: The Parmesan cheese adds some protein to the casserole, while the addition of mozzarella enhances the dish’s texture and flavor.
Variations and Substitutions
There are plenty of ways to customize this recipe to suit your tastes or dietary needs. Here are a few ideas:
- Dairy-Free Version: To make this casserole dairy-free, you can substitute the heavy cream with coconut milk or cashew cream. Replace the cheese with nutritional yeast for a cheesy flavor, or use a dairy-free cheese alternative.
- Gluten-Free Version: This recipe is naturally gluten-free as long as you use gluten-free breadcrumbs. You can also substitute the breadcrumbs with crushed almonds or gluten-free panko for a crunchy topping.
- Add More Vegetables: If you’d like to increase the vegetable content, you can add spinach, cherry tomatoes, or even mushrooms to the casserole. Just sauté them along with the garlic and onion to bring out their flavors.
- Add Protein: For a more substantial meal, you can add grilled chicken or turkey sausage to the casserole. Chop them into bite-sized pieces and layer them between the zucchini slices before baking.
- Low-Carb/Keto Version: If you’re following a ketogenic diet, you can use almond flour instead of breadcrumbs and add more cheese for extra fat content.
Conclusion
The Garlic Parmesan Zucchini Casserole is a versatile, healthy, and delicious dish that makes the most of fresh zucchini. With its creamy sauce, rich flavors of garlic and Parmesan, and a crispy breadcrumb topping, it’s a crowd-pleaser that works as a side dish or even as a vegetarian main. Whether you’re feeding a family, prepping for a meal, or looking for a dish that brings comfort and nutrition together, this casserole fits the bill.
Garlic Parmesan Zucchini Casserole Recipe

Ingredients
- 4 medium zucchinis, sliced into 1/4-inch thick rounds
- 1 tablespoon olive oil
- 3 cloves garlic, minced
- 1/2 cup grated Parmesan cheese (or more for topping)
- 1/2 cup shredded mozzarella cheese (optional for extra gooeyness)
- 1/2 cup breadcrumbs (preferably whole wheat or panko)
- 1/4 teaspoon salt
- 1/4 teaspoon black pepper
- 1/2 teaspoon dried Italian seasoning (or oregano)
- 1/4 teaspoon red pepper flakes (optional, for a little heat)
- Fresh parsley, chopped (for garnish)
Instructions
- Preheat the oven to 375°F (190°C) and lightly grease a 9x9-inch baking dish with olive oil or cooking spray.
- Prepare the zucchini: Slice the zucchinis into rounds and place them in a large bowl. You can also cut them into half-moons if you prefer.
- Sauté the garlic: In a large skillet, heat 1 tablespoon of olive oil over medium heat. Add the minced garlic and sauté for 1-2 minutes, until fragrant. Be careful not to burn the garlic.
- Combine the zucchini with garlic: Add the sliced zucchini to the skillet and sauté for 5-7 minutes, just until slightly softened. Stir occasionally. You don't want to cook them all the way through, as they will bake further in the casserole.
- Make the casserole mixture: In a bowl, combine the Parmesan cheese, mozzarella (if using), breadcrumbs, salt, pepper, Italian seasoning, and red pepper flakes. Toss to combine.
- Assemble the casserole: Spread the sautéed zucchini mixture evenly in the prepared baking dish. Sprinkle the cheese and breadcrumb mixture over the top, making sure to cover the zucchini completely.
- Bake: Place the casserole in the preheated oven and bake for 20-25 minutes, or until the top is golden brown and the zucchini is tender.
- Garnish and serve: Remove the casserole from the oven and sprinkle with fresh chopped parsley before serving.