Zucchini Casserole Recipe

Zucchini casserole is the perfect cheesy one-tray-bake, with a crispy breadcrumb topping and tons of flavor. It's a great dish to make for a weekend brunch or as a lighter side for chicken or steak, says food blogger and photographer Ksenia Prints of At the Immigrant's Table.

It's one of those classic all-American tray bakes, a casserole dish that tastes both comforting and nostalgic. With perfectly cooked zucchini that melts into a delicious mix of flavors, covered with a crispy Parmesan and breadcrumb topping, it's a dish you'll want to make again and again.

Whether you're cooking for a crowd or just looking for leftovers for the week, the zucchini casserole also reheats very well. It tastes great with a dollop of marinara sauce on the side, if you're looking to spice it up with some Italian flavors!

So, don't spend time eating sad frozen casseroles. Instead, make this easy, classic zucchini casserole for a very tasty treat.

Gather the ingredients for zucchini casserole

The ingredients you'll need to have on hand to prepare our zucchini casserole are simple and easy to find at any grocery store. From the produce aisle, you'll want to grab four zucchini. Green zucchini is the most typical to use, but if you have access to yellow summer squash, feel free to mix and match.

While you're in the produce section, also grab an onion and some garlic. These will be your seasonings or building blocks of flavor. Dried oregano is the only other seasoning this recipe calls for, but you can go for fresh oregano or basil as well. Other than that, all you'll need are eggs, your preferred type of shredded cheese, some shredded Parmesan, and the breadcrumbs of your choice.

Slice the zucchini and onion

As we get ready for cooking, let's get the prep work done and out of the way. It'll get you that much closer to eating, which is where most of us would like to be at, anyway!

Slice the zucchini (peel on) into rounds of about half an inch. We recommend cutting at a bit of a diagonal — that way, you get longer, prettier slices that will have more flavor as they cook. Smaller, thinner pieces can fall apart in a casserole's sojourn in the oven.

Dice the onion into cubes. If you want a more pronounced onion flavor, you can also opt for thin slivers in this zucchini casserole. Mince the garlic finely.

Preheat the oven to 350 degrees Fahrenheit. Then, oil or spray a casserole dish with cooking spray.

Sauté the vegetables in a pan

Because you want the casserole's time in the oven to be just long enough that the cheese melts but the breadcrumbs don't burn, give your veggies a quick sauté in a pan prior to combining everything in a casserole dish. This helps brown the outside of the zucchini, builds up layers of flavor, and helps get rid of some of that moisture that zucchini is known for. After all, you don't want a soggy casserole.

Preheat a large pan to medium heat. Add half the canola oil. Then, add the squash, onion, garlic, dried oregano, salt, and pepper, and stir to combine. Sauté the vegetables, stirring occasionally, for ten minutes, until they are tender and the zucchini can be easily pierced with a fork. Remove from heat, and set aside.

Make the egg mixture for zucchini casserole

While the zucchini and other veggies are cooking, you want to make the egg mixture that's going to help hold the casserole together.

In a large bowl, combine the eggs, salt, and black pepper. Whisk it all together. Make sure you're using a large enough bowl to contain all the zucchini filling. Otherwise, you'll have to do some creative rearranging, and we don't want to cause you any frustration in what should be an easy, breezy recipe! So, in short, grab a large bowl for your eggs. Add the cooked vegetables to the egg mixture, then stir to combine.

Combine the ingredients in a casserole dish

Grab your prepared casserole dish, because it's time to assemble your zucchini casserole. If you haven't done so yet, oil or butter the dish to prevent a sticky casserole situation. You can also use an oil spray.

Transfer the zucchini and egg mixture into the prepared casserole dish. Try to layer it in a single layer as much as possible. Top with the shredded cheese. If you're feeling particularly cheesy, feel free to increase the amount.

Mix the crumb topping for zucchini casserole

In a separate bowl, mix the Parmesan cheese, breadcrumbs, and remaining tablespoon of oil. Stir to combine. You should have breadcrumbs interspersed with Parmesan strands, dotted with ground black pepper. The oil helps everything stay more cohesive, so don't skip it.

Sprinkle the breadcrumb mixture on top of the shredded cheese layer in the baking dish. Drizzle lightly with a bit more oil, if desired, for a browning effect on the top of your casserole.

Bake your zucchini casserole

Place the casserole dish into an oven preheated to 350 degrees Fahrenheit. Don't forget to use oven gloves whenever opening a hot oven!

Bake the zucchini casserole at 350 degrees Fahrenheit for 30 to 35 minutes, until the cheese is melted and bubbly and the vegetables are tender and fully cooked. The crispy breadcrumb topping should be browned and the Parmesan and breadcrumbs should have become a cohesive mixture. Remove from the oven, and serve to the table immediately.

Serve zucchini casserole hot from the oven, with a dollop of marinara sauce

Serve your zucchini casserole immediately for the perfect cheesy taste, chewy texture, and nostalgic, comforting flavor. We like to dollop a little bit of marinara sauce on each plate and to sprinkle more dried or fresh herbs (oregano and basil are best here).

The resulting casserole is an Italian-American mix of flavors that immediately takes you back to grandma's house, school potlucks, and your favorite pizzeria all at once. If you're saving the leftovers, zucchini casserole reheats very well in the microwave or oven. It will keep in an airtight container in the fridge for five days.

Tasty zucchini casserole
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Zucchini casserole is the perfect cheesy one-tray-bake, with a crispy breadcrumb topping and tons of flavor. It's a great dish to serve at brunch or as a side.
Prep Time
10
minutes
Cook Time
45
minutes
Servings
6
servings
zucchini casserole slice
Total time: 55 minutes
Ingredients
  • 4 zucchini (about 2 pounds), sliced (about 6 cups total)
  • 1 onion, diced
  • 2 eggs
  • 1 1/2 cups shredded cheese (cheddar, mozzarella, or a blend)
  • 1/2 cup shredded Parmesan cheese
  • 1/2 cup breadcrumbs
  • 1 garlic clove, minced
  • 2 tablespoons canola oil
  • 1/2 teaspoon salt
  • 1/4 teaspoon pepper
  • 1 tablespoon dried oregano
Directions
  1. Preheat oven to 350 degrees Fahrenheit. Oil or spray a casserole dish with cooking spray.
  2. Slice zucchini. Dice onion. Mince garlic.
  3. Preheat a large pan to medium heat. Add 1 tablespoon of oil. Add zucchini, diced onion, minced garlic, dried oregano, salt, and pepper. Cook vegetables, stirring occasionally, for ten minutes, until they are tender and the zucchini can be easily pierced with a fork. Remove from heat and set aside.
  4. In a large bowl, combine eggs, salt, and black pepper. Whisk it all together. Add vegetables to egg mixture. Stir to combine.
  5. Transfer the zucchini mixture into the prepared casserole dish. Try to layer in a single layer. Top with shredded cheese.
  6. In a separate bowl, mix Parmesan cheese, breadcrumbs, and remaining 1 tablespoon of oil. Sprinkle on top of shredded cheese layer in baking dish.
  7. Bake zucchini casserole at 350 degrees Fahrenheit for 30 to 35 minutes, until cheese is melted and bubbly and vegetables are tender. Sprinkle with additional oregano. Serve immediately.
Nutrition
Calories per Serving 296
Total Fat 19.8 g
Saturated Fat 8.5 g
Trans Fat 0.4 g
Cholesterol 90.6 mg
Total Carbohydrates 14.4 g
Dietary Fiber 2.4 g
Total Sugars 5.3 g
Sodium 562.3 mg
Protein 16.3 g
The information shown is Edamam’s estimate based on available ingredients and preparation. It should not be considered a substitute for a professional nutritionist’s advice.
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