Zucchini Casserole

This easy Zucchini Casserole has the BEST flavor! It's cheesy and perfectly seasoned with a crunchy panko breadcrumb topping. It's the best side dish recipe that can be easily transformed into a main course.

Prep Time15

Cook Time40

Total Time55

Course: Side Dish

Cuisine: American

Servings: people

Calories: 263kcal

Author: Stephanie

Ingredients

Filling

9 cups shredded zucchini about 2 ½ lbs. whole zucchini
1 ½ teaspoons salt
2 teaspoons olive oil
1 small yellow onion finely diced
3 cloves garlic minced
3 large eggs whisked
¼ cup heavy cream
1 teaspoon Dijon mustard
1 ¼ cup panko breadcrumbs
1 cup shredded Parmesan cheese
½ teaspoon EACH: oregano, basil, garlic salt, parsley
¼ teaspoon EACH: paprika, black pepper
1 ¼ cups shredded cheddar cheese for the top of the casserole

Breadcrumb Topping

¼ cup panko breadcrumbs
1 tablespoon butter melted

US Customary - Metric

Instructions

Preheat oven to 375° F.
Shred the zucchini (with the skin on unless jumbo sized, see notes) and transfer it to a colander. Sprinkle with a light layer of salt, I use 1 ½ teaspoons. Top with paper towels and let sit for 15 minutes (or longer) while you measure out remaining ingredients.
Heat olive oil in a small skillet over medium heat. Add the onions and soften for 5 minutes. Add the garlic and soften for 2 minutes. Remove and set aside.
Use paper towels to press down and absorb all excess moisture from the zucchini. Not so much that you have no zucchini left, but enough so that it's not excessively wet. (Note: This is a forgiving recipe. I have removed too much liquid before, and also not quite enough- it's always amazing either way. It sets more as it stands after baking as well.)
Transfer to a large bowl along with the sauteed onions and garlic, whisked eggs, heavy cream, Dijon, 1 ¼ cup panko, parmesan cheese, and seasonings. Stir to combine.
Transfer to a lightly greased 9 x 13-inch casserole dish. Top with cheddar cheese.
Cover and bake for 35 minutes.
Combine the 1/4 cup panko and melted butter for the topping and sprinkle it over the casserole. Bake uncovered for 15 minutes. If desired, broil at 425 for 1-2 minutes to add more color to the top. Watch it carefully during this time.
Remove and let stand for 5 minutes prior to serving.

Notes

Pro Tips

You can leave the skin on the zucchini unless it's jumbo sized, in which case the skin may be bitter.
Yellow squash can be used in combination with the zucchini in this casserole.
Gruyere cheese can be used along with the Parmesan cheese.
It's best to bake right after assembling as opposed to making this ahead of time, as the zucchini will continue to release water upon being salted.
4 medium zucchini is enough to produce 9 cups shredded.
Shred the cheese from a block for best flavor and meltability. I use Belgioioso Parmesan and Cracker Barrel Sharp Yellow Cheese.
Optional Additions: Finely shredded carrots, sauteed mushrooms and/or peppers, or even some cooked ground sausage make nice add-ons to this casserole. I would add an extra egg for additional binding if you add more ingredients to this dish.
For more zucchini recipes, try my Zucchini Soup, Zucchini Parmesan, and Zucchini Crust Pizza! And be sure to try my Eggplant Casserole recipe.

Storage:

Store in an airtight container and refrigerate for up to 3 days (leftovers are even good cold!) or freeze for up to 3 months. I do enjoy freezing and reheating leftovers.
Reheat leftovers in a lightly greased, uncovered casserole dish at 350° for 20-25 minutes or until heated through.

Nutritional information is an estimate and is per serving. This recipe makes 8 servings.

Nutrition