This zucchini casserole is pure summer comfort in under 30 minutes. Thinly sliced zucchini sauté briefly, then baked until bubbly and golden under a Parmesan-breadcrumb crust. It's light without being skimpy-no heavy eggs or cream-and perfect for pairing with grilled meats or enjoying as a warm, veggie-first side any night of the week.
While gardens and markets are overflowing with beautiful summer squash, this zucchini gratin is my favorite way to enjoy it-simple, fresh, and never heavy. Instead of burying the vegetables in cream, mayonnaise, or mounds of cheese, I keep it light so the zucchini flavor shines, finishing with just enough Parmesan and crisp gluten-free breadcrumbs for a satisfying crunch.
Zucchini Casserole Recipe Snapshot
- Great for all of that summer zucchini.
- Easy and quick recipe.
- Nice summer side dish.
Here's another easy summer zucchini casserole with tomatoes and herbs.
Ingredients You'll Need
- Oil: I prefer olive oil but a neutral healthy oil or avocado oil is good too.
- Zucchini: Green zucchini is what I used the first time but you can mix yellow and green for more color.
- Shallot: Petite member of the onion family with a lovely flavor, and a classic in French cooking.
- Garlic: For that marvelous pungent flavor. Fresh is best, but the tube puree is good too (just read the label for additives).
- Fresh herbs: Fresh parsley and fresh thyme leaves make a terrific combo.
- Breadcrumbs: Either homemade toasted breadcrumbs or store-bought, and gluten -free if needed.
- Parmesan: For a nice crisp, crunchy, crust.
Please see the recipe card for measurements.
Substitutions and Variations
- Swap dried thyme for fresh if fresh is not available. Use ⅓ the amount.
- Swap Pecorino Romano or Piave for the Parmesan cheese.
If you eat wheat, panko crumbs are a good substitution for regular toasted breadcrumbs. - Substitute chopped onion for the shallot.
For another summery side with zucchini, try this Mexican squash with the nice addition of corn. For a main dish zucchini recipe try this cheesy stuffed zucchini recipe called Zucchini Involtini.
How to Make a Zucchini Casserole
Trim off the ends, then cut zucchini in half lengthwise. Cut the halves into thin half moons about. Cook the zucchini quickly in a hot pan with olive oil for just a few minutes until it is starting to brown a bit at the edges.
Turn the heat down, add shallot and cook a minute or two, then add the garlic and cook for 30 seconds more. Stir in fresh herbs.
Pour zucchini into a shallow casserole baking dish that is broiler-safe. The one I use is an 8″x12″ oval baking dish and about 2 quarts. The key is to choose a shallow baking dish, no matter what shape, so everyone gets a good serving of the crunchy topping.
Lightly oil the dish so nothing sticks. Pour in the zucchini, top with a combination of gluten-free (or wheat) breadcrumbs and Parmesan. Pop under a hot broiler for a minute or two until golden and enjoy!
Serving Suggestions
Serve alongside of grilled meats in summertime or easy baked chicken breasts. Zucchini casserole is bets enjoyed the day of cooking as it will soften up (but it still taste good).
Looking for more zucchini recipes? Try this terrific zucchini muffins. Light, tender muffins great for breakfast or a snack.
Recipe FAQs
It depends on the ingredients. Some recipes that are heavy with eggs and cheese may take up to 45 minutes in the oven. Rather than baking, this recipe starts with a quick saute and finishes under the broiler for a crispy top crust. Faster and easier.
Yes, here is how you make a zucchini casserole without eggs. Chop zucchini into bite-sized pieces, saute until crisp-tender and add a little chopped shallot, pour into an oiled shallow casserole and top with a parmesan crumb topping, then broil until browned and crisp. No eggs needed! It's lighter, easier zucchini casserole.
Variations on a zucchini casserole include adding different types of cheese, incorporating other vegetables like tomatoes or bell peppers, using different herbs and spices, or adding a protein such as cooked chicken, ground beef, or sausage.
More Summertime Side Dish Recipes
Looking for more super summer side dish recipes? Try these or take a look at this link for more summertime recipe ideas.
⭐️Did You Make This?
If you make this zucchini casserole, please comment and let me know, and if you loved it, please give it a 5 star rating. They really help other readers. Any questions? Just ask. I'm here to help.
📖 Recipe
Zucchini Casserole with Parmesan Crust
Equipment
- 1 quart shallow baking dish, broiler safe
Ingredients
- 2 tablespoons olive oil divided use
- 2 pounds zucchini about 4 medium, 8 ounces each
- 1 large shallot finely chopped
- 2 large garlic cloves finely chopped
- 2 tablespoons freshly chopped parsley
- 1 tablespoon freshly chopped thyme leaves or 1 teaspoon dried
- ⅓ cup grated Parmesan cheese or Pecorino Romano or Piave for the Parmesan cheese.
- ⅓ cup toasted breadcrumbs, gluten-free or wheat see notes below
- ¼ teaspoon sea salt
- ¼ teaspoon ground black pepper
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Instructions
Set up the Broiler
- Position an oven rack in the middle of the oven. Preheat the broiler. Lightly oil a shallow 1-quart broiler-safe baking dish with olive oil or spray it with avocado oil.
Make the topping
- Combine the breadcrumbs, Parmesan cheese, and 1 tablespoon of olive oil in a small bowl. Stir until the crumbs are evenly coated and set aside.
Trim Zucchini
- Trim the ends from the zucchini, then cut each one into quarters lengthwise. Lay the quarters flat and, holding your knife parallel to the cutting board, trim away the seedy, spongy center. Cut the zucchini into bite-sized pieces.Removing the soft center helps the zucchini stay firmer and prevents the casserole from becoming soggy.
Cook Zucchini and Shallots
- Heat the remaining 1 tablespoon of olive oil in a large 12-inch sauté pan over medium-high heat. Add the zucchini and cook, stirring and turning frequently, until just beginning to soften and lightly brown around the edges, 5-6 minutes. Do not cook it until completely tender.Transfer the zucchini to a plate so it does not continue cooking while you prepare the shallot and garlic.
Cook the Shallot and garlic
- Reduce the heat to medium low. Add the shallot to the same pan and cook for 2-3 minutes, until softened. Add the garlic and cook for 30 seconds, stirring, until fragrant. If the pan is dry add a few extra drops of oil.Stir in the fresh thyme, parsley, salt, and black pepper. Return the zucchini to the pan and toss briefly to combine and coat it with the shallot, garlic, and herbs.
Broil the Casserole
- Transfer the zucchini mixture to the prepared baking dish and spread it into an even layer. Sprinkle the Parmesan breadcrumb mixture evenly over the top.Broil until the topping is golden brown and crisp. Watch closely, as breadcrumb toppings can brown quickly under the broiler, even in a minute or 2. Don't walk away from the broiler. Cool a bit and serve warm.
Notes
Nutrition
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Kate S says
Easy and delicious!
Sally Cameron says
Thanks for commenting Kate! Glad you enjoyed it!
Lois says
Fabulous! Nothing more can describe it if you are zucchini lover and even if you are not!
Mrs. O says
The recipe says, “1 1/2 tablespoons olive oil divided use”. I only see the olive oil being used to fry the zucchini. Did I miss a step?
Sally Cameron says
Hi Mrs. O. You mix part of the olive oil with the topping, then use the rest to cook the zucchini. I checked the recipe and it's there in the description, but I did clarify it a bit. Hope that helps! Thanks for the question and hope you enjoy this. I think I'll make it tonight! I also foxed a photo, so thanks again.
Kristen says
Thank you for sharing this recipe - I made it over the weekend and it was fantastic! FYI - After dinner we had half the casserole left over, and with no room in the fridge I decided to experiment. I blended the remaining portion in a food processer and mixed with a little sour cream / greek yogurt.... let me tell ya it makes one HECK of an amazing dip. Like, reeeally good.
Sally says
Thanks for shring that tip Kristen! Sounds fantastic. I'd never have thought of turning leftovers into a dip! Glad it worked so well for you!Very creative!
Mary@SiftingFocus says
Sally, I'm always looking for new and delicious twists on preparing zucchini. Love the healthy and simple approach you took in this recipe.
Madonna/aka/Ms. Lemon says
Our family calls zucchini our new potato. This looks delish.