Got zucchini? At the end of summer, markets and gardens have it in abundance. Enjoy one of my favorite green vegetables in a light, easy zucchini casserole. It’s my take on a classic gratin, topped with gluten-free breadcrumbs and Parmesan. Delicious, crunchy, and a nice summer side dish.

Zucchini Casserole with Parmesan Crumb Topping
Here is the way I’ve been cooking zucchini lately; casserole or gratin style. While many recipes featuring zucchini bury it in cream, mayonnaise, and mounds of cheese, this recipe is light and crunchy as I don't like soggy zucchini.
Shallots, garlic and fresh herbs give it flavor. A little gluten-free breadcrumbs and Parmesan make the crisp topping. Not gluten-free? Swap regular breadcrumbs or panko.
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Ingredients
Zucchini: I use small squash that are about the length of my hand.
Shallots: If you are not familiar with shallots, let me say that you should be! Always in my pantry, these petite members of the onion family and have a lovely sweet flavor. A basic in classic French cooking, a shallot loos like a cross between a garlic clove and an onion. Shallots have a brownish-coppery paper skin and look like a big garlic clove.
Instructions
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.
Shallow Casserole Dish
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!
Homemade Breadcrumbs (GF)
Homemade bread crumbs are so much better than store bought and so easy to make. I keep a container in the fridge for quick use. If you're interested find the recipe link here. I’ll do most of a loaf at once so I always have breadcrumbs to use in a gratin or to add crunch to simple vegetables.
📖 Recipe
Easy Zucchini Casserole with Parmesan Crust
Equipment
- Shallow, broiler-safe casserole dish 2 quart size
Ingredients
- 1 ½ tablespoons olive oil divided use
- 1 ½ pounds zucchini 680 grams, about 7 small
- 1 large shallot finely chopped
- 2-3 garlic cloves finely chopped
- 2 tablespoons freshly chopped parsley
- 2-3 teaspoons freshly chopped thyme leaves or 1 teaspoon dried
- ⅓ cup toasted breadcrumbs gluten-free or whole wheat
- ⅓ cup grated Parmesan cheese
- ¼ teaspoon Sea salt
- ¼ teaspoon ground black pepper
Instructions
Set up the Broiler
- Adjust oven rack to the medium level or one level up and heat the broiler. Lightly oil a shallow 2 quart, broiler safe baking dish with a little of the olive oil.
Trim Zucchini
- Trim ends from zucchini, then cut them in half lengthwise. Chop zucchini halves into thin half moons about ½″ wide. Combine breadcrumbs and Parmesan along with ½ tablespoon of olive oil in a small bowl and stir together until well blended.
Cook Zucchini and Shallots
- Heat the other 1 tablespoon of olive oil in a large saute pan over medium heat. Add zucchini to the pan and cook until it is softened and starting to brown at the edges, stirring and turning frequently. Sprinkle in the shallot and cook 1 minute. Add garlic and cook 30 seconds. Stir in herbs.
Bake Casserole
- Pour zucchini into baking dish and spread the crumb topping evenly over top. Broil until casserole has a golden crunchy top. Serve hot.
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.