Zucchini Casserole

This casserole recipe is one of my go-to side dishes or vegetarian meals. Zucchini rice casserole is perfect as a side dish for Thanksgiving. Try it instead of baked corn or mac and cheese. It’s also hearty enough for a meal on Meatless Mondays.

Summer always leads to plentiful zucchini and this casserole recipe is a great way to use it, as is homemade zucchini bread, air fryer zucchini fries or zucchini chips. We also just love this grilled vegetable salad with lots of zucchini and summer squash, topped with tangy goat cheese. Vegetable fritters with grated zucchini, carrots, and bell peppers are a popular option, too. Be sure to check out my entire list of zucchini recipes.

Homestyle Zucchini Casserole Recipe

This casserole is comfort food. It’s hearty, cheesy, and creamy without being overly heavy. You know I love my salads as much as the next girl but there are those times when you want food that’s more cozy and comforting, like a blanket to wrap around you when you’re having one of those days.

Large or small zucchini are fine. Do you have an abundance of zucchini in your garden? Try this recipe! You can use those zucchini that may have gotten a bit too large. Since they are shredded, the size doesn’t really matter all that much.

Even vegetable “haters” love this casserole. This casserole is perfect for those who don’t like crisp vegetables. It’s similar to cheesy potatoes or a gratin. The zucchini is shredded before combining it with rice, cheese and eggs.

It has a crispy topping. A mix of panko bread crumbs (these are the kind I buy) with Italian seasoning and Parmesan cheese gives the casserole a crispy crust that seals the deal and makes this recipe a total winner. If you like casseroles topped with Ritz crackers, that’s a good alternative, too. You can also make your own bread crumbs!

Ingredient Notes

• Zucchini: Big or small, size doesn’t really matter in this recipe. You’ll need about one and a quarter pounds. Since zucchini varies so much in size, it’s best to weigh it to get the correct amount although a little more or less won’t affect the recipe much. If it’s extremely large and has a lot of seeds, make sure to avoid using those.
• Onion: Use whatever type of onion you happen to have on hand. A plain yellow cooking onion is fine.
• Rice: You’ll need 2 cups of cooked rice. You can use white or brown rice. The cooking time of this recipe does not include cooking the rice.
• Sour Cream: To keep this casserole a bit healthier, I use reduced fat. Full fat is fine but stay away from fat free sour cream which contains additives
• Plain Greek Yogurt: Again, choose whichever type of plain Greek yogurt you prefer. Nonfat yogurt is fine because it does not contain any additives. Full fat or 2% yogurt will make the casserole creamier. Just make sure it’s unflavored and unsweetened.
• Eggs: A couple of eggs add protein and substance to the casserole, helping it to hold together.
• Sharp Cheddar Cheese: The sharper, the better! There’s plenty of flavor in sharp cheese which allows you to use less.
• Parmesan Cheese: Again, Parmesan cheese has lots of flavor so you don’t need to add as much. You’ll put some in the casserole and some in the topping. Use grated cheese (the stuff in the green container is fine).
• Italian Seasoning: This blend of dried herbs usually contains thyme, oregano, and basil. If you don’t have it in your pantry, just substitute plain dried basil or oregano, or even dried parsley flakes.
• Garlic Powder: Garlic powder is an easy-to-use form of garlic. It’s dehydrated garlic that is ground into a fine powder. Garlic powder and garlic salt are not the same thing.
• Salt & Pepper: Simple seasonings but you wouldn’t want to leave them out.
• Panko Bread Crumbs: I like to use whole wheat panko for the topping but it isn’t always available. Regular panko is fine. Panko bread crumbs are coarser and airier than fine bread crumbs, giving the topping more crispness. By the way, it’s easy to make homemade bread crumbs and it’s a great way to use day-old bread.

How To Make Zucchini Casserole

If you don’t happen to have cooked rice on hand, you’ll want to get that going first. I almost always have cooked rice in the freezer. I make double or triple of what I need and freeze the rest in 2 cup portions. It’s super handy to have and thaws quickly.

Shred the cheese in a food processor, remove it, and then coarsely shred the zucchini.

Meanwhile, get the oven preheating and spray a baking dish with nonstick spray. Combine the rice, sour cream, yogurt, cheddar cheese, half the Parmesan cheese, the beaten eggs, and seasonings.

Add in the zucchini.

Stir to combine all the ingredients.

Scrape it all out into the baking dish.

In a small bowl, mix together the panko, the remaining Parmesan cheese, and Italian seasoning.

Sprinkle the topping over the casserole and pop it into the oven.

Bake it for an hour. It should be lightly golden and set in the middle (not jiggly or wet).

Recipe Variations

• Use brown rice instead of white rice. Cooked quinoa, farro, or even barley can be substituted. Brown rice has more nutritional value than white rice and it’s filling, nutty, and flavorful.
• Choose your cheese. Don’t have any cheddar cheese in the house? Go ahead and use what you happen to have.
• Add more veggies (up to a cup). Finely chopped red bell peppers, mushrooms, or broccoli are good additions and can add a lot of flavor.
• Meat lovers can add a cup of cubed ham or cooked bacon to the the casserole.
• Topping idea: Zucchini casserole tastes great with a Ritz cracker topping. Substitute crushed crackers for the panko topping. Crushed potato chips are good, too.

Make-Ahead Ideas

To speed up the cooking time, make a big batch of rice a day ahead, either white or brown, whichever you prefer. Try Instant Pot white rice or Instant Pot brown rice, if you have an Instant Pot. It’s a very easy way to prep rice.

Cooked rice can be refrigerated for up to four days or pop it in the freezer (in reclosable freezer bags) for up to two months. It’s so handy for salads, fried rice, or side dishes.

Storage & Reheating Tips

Store leftovers in the refrigerator for up to 4 days. This zucchini casserole doesn’t freeze well.

Reheat single servings gently in the microwave. Larger quantities can be reheated in the oven. Heat at 350°F for 20 to 30 minutes or until heated through.