If you’ve followed my blog for a while, you know casseroles are usually my cold-weather comfort food. There’s something about pulling a bubbling, golden-brown bake from the oven that makes even the chilliest day feel cosy. All winter, I found myself experimenting with new casserole ideas—sometimes classic, sometimes with a twist. Check them out at the bottom of this page.
But when the first warm breeze of summer rolled in, I realised my casserole cravings weren’t going anywhere. Instead, I wanted something lighter, fresher, and packed with seasonal produce.
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Why I Can’t Get Enough of This Zucchini Casserole Recipe This Summer
With summer squash in abundance during the warmer season, I started experimenting with zucchini casserole recipes.
If you’re like me and end up with an abundance of zucchini each summer (thanks, local markets and generous neighbours!), you’ll love how this dish transforms simple ingredients into something truly special.
I adore using fresh zucchini because it’s so versatile and loaded with nutrients. Plus, it’s a great way to sneak extra veg onto the table for the entire family.
Cooking Summer Recipes with Seasonal Produce
Cooking with what’s in season just makes sense. The flavours are better, the produce is more affordable, and you get that unbeatable feeling of eating food that’s travelled only a short distance. This summer, zucchini is at its peak—crisp, sweet, and perfect for tossing into everything from salads to this cheesy zucchini casserole.
I’ve spent the last couple of months testing this recipe with different combinations of cheeses, herbs, and toppings. My goal? A creamy casserole that’s light enough for a summer dinner, but still has that irresistible crispy top.
The result is a zucchini casserole recipe that’s become one of my favourite ways to use up a lot of zucchini, especially when you need a perfect side dish that pleases everyone.
What Makes This Zucchini Casserole Recipe a Winner
You’re probably wondering what sets this zucchini casserole recipe apart from the rest, and whether this is the recipe you should try. I mean, there are a few zucchini casserole recipes out there, how do you choose which one is worth your time?
For starters, it’s all about balance—creamy on the inside, with just the right amount of crispiness on top. I use a mix of sour cream, parmesan cheese, and a touch of sharp cheddar for that rich, tangy flavour. Fresh zucchini slices and juicy tomatoes keep things light and summery, while Italian herbs and fresh parsley add a burst of freshness.
You won’t find any complicated steps or hard-to-find ingredients here. Just real, simple ingredients that come together in a large bowl and bake beautifully in your favourite casserole dish. If you’ve got a couple of medium zucchini (or even a large zucchini), you’re already halfway there.
And for anyone watching their carbs, you can easily swap out the breadcrumbs for a mix of almond flour and parmesan. It’s a great way to keep things low-carb without sacrificing that golden brown crunch.
Ingredients You’ll Need for This Cheesy Zucchini Casserole
- 3–4 medium zucchini (or enough zucchini to make about 6 cups of thin slices)
- 2 large tomatoes, sliced
- 1 cup sour cream (room temperature)
- 1 cup parmesan cheese, grated
- 1 cup sharp cheddar cheese, grated
- 2 eggs, room temperature
- 1 small sweet onion, finely chopped
- 2 cloves garlic, minced (or 1 tsp garlic powder)
- 2 tbsp fresh parsley, chopped (or 1 tbsp dried Italian herbs)
- 1/2 cup panko breadcrumbs (or almond flour + parmesan for low carb)
- 2 tbsp olive oil
- 1/2 tsp salt
- 1/2 tsp black pepper
- Optional: 1/2 cup mozzarella cheese for extra gooeyness
Step-by-Step Guide: How to Make the Best Zucchini Casserole Recipe
Prepping Your Zucchini Slices
First things first—zucchini has a high water content, which can lead to a watery casserole if you’re not careful. Here’s my tried-and-true method for avoiding excess moisture:
- Wash and dry your fresh zucchini.
- Slice into thin rounds using a sharp knife or an electric shredder like this one.
- Lay the slices on a layer of paper towels and sprinkle with a little salt.
- Let them sit for 15–20 minutes. You’ll see a lot of water bead up on the surface.
- Pat dry with more paper towels to remove excess water and salt.
This step makes all the difference for a creamy, not soggy, zucchini casserole recipe.
Mixing the Zucchini Mixture
Grab your largest mixing bowl. Add the zucchini slices, chopped onion, minced garlic, and tomato slices. Toss gently with olive oil and pepper. Do not add anymore salt as the zucchini may be already salty from the previous step. I find that using clean hands or gloves gets the job done the best.
In a small bowl, whisk together the eggs, sour cream, half the parmesan cheese, and all the cheddar. Pour this creamy mixture over the veggies and stir until everything is well-coated. Be gentle and don’t turn all the veggies into a mush.
Layering and Baking
Grease your favourite baking dish or casserole dish with a little olive oil. Spoon in half the zucchini mixture, sprinkle with a handful of breadcrumbs (or your low-carb almond flour mix), and layer in a few tomato slices. Repeat with the remaining mixture and finish with the rest of the parmesan, a sprinkle of breadcrumbs, and a drizzle of olive oil.
Bake at 180°C (350°F) for 35–40 minutes, or until the top is golden brown and the casserole is bubbling at the edges. If you love an extra crispy top, pop it under the grill for 2–3 minutes at the end of cooking.
Let it rest for 10 minutes before serving—this helps the casserole set and makes slicing easier.
Tips for the Perfect Cheesy Zucchini Casserole
- Always extract excess moisture from zucchini before baking using the method I described before.
- Use room temperature eggs and sour cream for a smoother mixture.
- For a richer flavour, add a handful of gruyere cheese or feta cheese.
- Fresh basil or parsley on top adds a burst of colour and flavour.
- Store leftovers in an airtight container in the fridge for up to 3 days. It reheats beautifully!
Pressure Cooker Option for This Zucchini Casserole Recipe
Short on time? You can make this zucchini casserole recipe in a pressure cooker or Instant Pot.
- Prepare the zucchini slices as above (don’t skip the salting step).
- Mix everything together in a large bowl.
- Pour the zucchini mixture into a greased, oven-safe dish that fits your pressure cooker.
- Add 1 cup of water to the pressure cooker pot, set the casserole dish on a trivet, and seal the lid.
- Cook on high pressure for 10 minutes, then quick release.
- For a crispy top, transfer to a hot oven or grill for 5 minutes.
Why This Zucchini Casserole Recipe Is a Great Way to Eat Well
Zucchini Nutrition
Zucchini is low in calories (just 17 calories per 100g) and high in vitamin C, potassium, and fibre. It’s a great way to add bulk and nutrients without a lot of calories—perfect for anyone looking for lighter options.
Tomatoes
Tomatoes add a pop of colour and are rich in lycopene, an antioxidant linked to heart health. They also provide vitamin C and potassium.
Parmesan Cheese
Parmesan cheese is a good source of calcium and protein. It’s lower in lactose than many other cheeses, making it a good option for those who are sensitive.
Fun fact: Did you know zucchini is technically a fruit because it has seeds? And Parmesan must be aged for at least 12 months to earn its name in Italy.
Substitutions and Variations
- Low-carb: Swap panko breadcrumbs for a mix of almond flour and parmesan (about half and half)
- Extra creamy: Add a splash of heavy cream to the egg mixture.
- More protein: Stir in cooked ground beef or serve alongside chicken thighs or pork chops. It goes nicely with my Pork Chop with Herbs De Provence.
- Different cheeses: Try mozzarella cheese, feta cheese, or gruyere cheese for a twist.
- Add-ins: Yellow squash or even a bit of spinach to bump up the nutrients.
Storage, Leftovers, and Meal Prep
Leftover zucchini casserole keeps well in an airtight container in the fridge for up to three days. I often make a double batch and enjoy it for lunch the next day. If you want to freeze it, let the casserole cool completely and wrap it tightly before freezing for up to a couple of weeks.
Common Questions About This Zucchini Casserole Recipe
Lay the zucchini slices out on a paper towel, sprinkle with salt, let it sit for about 10-15 minutes and pat it dry with another paper towel. Repeat on the other side.
Both work! Just slice thick zucchini into thin slices and remove any large seeds for the best texture.
It’s a perfect side dish for grilled meats, but I’ve also served it with a simple green salad for a light dinner.
Absolutely. Assemble the casserole up to a day ahead and keep it covered in the fridge. Bake just before serving.
Zucchini Casserole Recipe with Parmezan and Tomato
Ingredients
- 3 –4 medium zucchini thinly sliced
- 2 large tomatoes sliced
- 1 cup sour cream
- 1 cup parmesan cheese grated
- 1 cup sharp cheddar cheese grated
- 2 eggs
- 1 small sweet onion chopped
- 2 cloves garlic minced
- 2 tbsp fresh parsley or 1 tbsp dried Italian herbs
- 1/2 cup panko breadcrumbs or almond flour + parmesan
- 2 tbsp olive oil
- 1/2 tsp salt
- 1/2 tsp black pepper
Instructions
- Preheat oven to 180°C (350°F).
- Salt zucchini slices and let sit for 15–20 minutes; pat dry.
- In a large bowl, mix zucchini, onion, garlic, tomatoes, olive oil, and pepper.
- In a small bowl, whisk eggs, sour cream, half the parmesan, and cheddar.
- Combine mixtures and layer in a greased baking dish.
- Top with remaining parmesan and almond flour or breadcrumbs, and a drizzle of olive oil.
- Bake 35–40 minutes until golden brown.
- Rest 10 minutes before serving.
Notes
Nutrition
Zucchini lovers, this is your new go-to! If you try this zucchini casserole recipe, let me know how it goes in the comments. And if you make any slight changes or have a favourite way to serve it, I’d love to hear about it—sharing ideas is half the fun in the kitchen.
Happy cooking!
