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Zucchini Casserole Recipe

This Baked Zucchini Casserole recipe has layers of zucchini and eggs in a cheesy, garlic cream sauce. High in protein and low in carbs, this casserole is a perfect Keto side dish the whole family will enjoy.

Love zucchini? Be sure to try our breakfast zucchini egg nests! Or give our zucchini rollups a try for dinner tonight!

Cheese and zucchini baked in a round baking dish.

Why This Casserole is Best

Whether you’re looking for a cheesy side dish, or a vegetarian meal, this baked zucchini casserole is always a good choice!

  • No more mushy zucchini! Salting the zucchini slices draws out excess water so the zucchini becomes fork tender, not mushy.
  • Keto and vegetarian friendly. This casserole is meat free but low carb to appeal to all kinds of eating styles.
  • Filling and satisfying. With tons of protein from eggs and cheese, this is a vegetable recipe that won’t leave you feeling hungry!
  • Easy side dish. Cheesy zucchini casserole goes perfectly with grilled chicken, meatloaf and all your favorite main courses.

Ingredient Notes

Ingredients needed for zucchini casserole recipe.
  • Zucchini – For more variety of color, use half yellow squash and half zucchini. Make sure to slice off the tops and bottoms of the zucchini and slice it very thin.
  • Kosher salt – The coarser salt granules make it ideal for drawing moisture from the zucchini. Coarsely ground sea salt works too. Want more flavor? Toss in a teaspoon of our Italian seasoning mix!
  • Cheese- You’ll need freshly grated cheddar and parmesan for the cream sauce. Save the mozzarella cheese for layering with the other casserole ingredients.
  • Heavy cream – Melting the cheese with this high fat cream creates a thick, rich sauce that covered the zucchini with amazing flavor.
  • Eggs – Beat the eggs before adding them to the casserole. They’re combined with the sauce and will become soft and fluffy when baked.

How to make zucchini casserole

Step by step photos showing how to make zucchini casserole.
  1. Prepare the zucchini.
  2. Place zucchini slices on a baking sheet lined with paper towels. Sprinkle kosher salt over the slices. Leave them for 15 minutes. Flip the zucchini over and repeat the salting process. Pat the zucchini dry with a towel and arrange it at the bottom of a round baking pan.
  3. Make the garlic parmesan sauce.
  4. Assemble and bake. Pour the cream sauce over the first layer of zucchini. Top with mozzarella cheese. Add another layer of each ingredient until all the zucchini, sauce and cheese has been used.
  5. Bake Zucchini Casserole for 20 minutes. The zucchini should be fork tender and ready to eat!

Serving Suggestions

  • Top each serving of cheesy zucchini with chopped parsley for a pop of fresh color.
  • Add a crunchy topping by sprinkling crushed pork rinds on top of the casserole before baking.

This casserole goes well with all kinds of grilled meats, steaks and even seafood. It’s heavy on the creamy, cheesy flavor so I recommend serving it with a main course that’s not drowning in sauce.

Zucchini casserole is also delicious served with salads. Try it with an Antipasto Italian Salad or this Chicken Caprese Salad to get plenty of veggies into your day!

Slice of zucchini casserole on a white plate for serving.

Recipe FAQs

Is zucchini keto?

Yes, zucchini is approved for keto diets. It’s high in water content and fiber with only about 2 net carbs per serving.

Can I make this casserole with egg whites only?

No, the casserole recipe will not work with egg whites only. The yolk provides necessary fats, liquid and protein to bind the casserole together. It also adds a richer flavor than egg whites alone would provide.

How do I keep zucchini from getting mushy?

Salting the zucchini, then patting it dry with a towel helps keep the zucchini from getting watery as it bakes. You should also be careful not to over cook the zucchini. It doesn’t need much time in the oven. As soon as it is easy to pierce with a fork, it is ready to eat.

How do you store leftover zucchini casserole?

Baked zucchini casserole tastes best enjoyed warm the same day it is made. Leftovers can be tightly covered and stored in the fridge.

More Low Carb Side Dishes

Yield: 6 servings

Baked Zucchini Casserole Recipe

This Baked Zucchini Casserole recipe has layers of zucchini and eggs in a cheesy, garlic cream sauce. High in protein and low in carbs, this casserole is a perfect Keto side dish the whole family will enjoy.

This Baked Zucchini Casserole recipe has layers of zucchini and eggs in a cheesy, garlic cream sauce. High in protein and low in carbs, this casserole is a perfect Keto side dish the whole family will enjoy.

Prep Time 15 minutes
Cook Time 20 minutes
Additional Time 15 minutes
Total Time 50 minutes

Ingredients

  • 3 small zucchini (4 cups sliced)
  • 2 teaspoons kosher salt
  • 2 Tablespoons olive oil
  • 1 yellow onion, diced
  • 2 cloves garlic, minced
  • 1 green onion
  • 1 cup heavy whipping cream
  • 1 cup shredded cheddar cheese
  • ¼ cup parmesan cheese, shredded
  • ½ teaspoon ground black pepper
  • 2 large eggs
  • 1 ½ cups crumbled fresh mozzarella cheese (can also use shredded)

Instructions

  1. Prepare the zucchini: Remove the top and bottom, and slice it thin. Place the zucchini slices in a large tray covered with a clean tea towel or paper towel. Sprinkle some salt on top so they’ll release excess water. Leave it for 10-15 minutes, and then repeat it on the other side. Then dry the zucchini using a clean towel. Take a 9’’ round baking pan, and arrange ⅓ -¼ of the zucchini slices on the base. Set aside.
  2. Preheat the oven to 400 degrees F. 
  3. Add two tablespoons of olive oil into a skillet and sauté onion and garlic until fragrant (about 2 minutes). Add sliced green onion (the white part only) and stir until the onion is translucent.
  4. To the skillet, over medium heat, add heavy cream, cheddar, and parmesan cheese; mix until smooth and slightly thickened. Remove from heat.
  5. Season cheese mixture with ground black pepper, and add beaten eggs. Whisk to combine. 
  6. Cover the zucchini slices with creamy sauce and mozzarella cheese. Repeat two to three more layers with the rest of the zucchini, the sauce, and mozzarella cheese.
  7. Bake this zucchini casserole for 20 minutes or until zucchini is fork-tender. Serve warm.

Notes

  • To avoid a watery dish, we salt the zucchini in the first step. If you skip this step, you may need to use a skimmer at the end to remove zucchini from dish (leaving behind some of the extra liquid).
  • Want to finish with a crunchy topping? Add crushed pork rinds to the top of the dish before baking.
  • Use a combination of yellow squash and zucchini for a pop of color.
  • Add fresh parsley after baking for some bright color if desired.
  • See blog post for more recipe tips and tricks!

Nutrition Information:

Yield:

6

Serving Size:

1

Amount Per Serving: Calories: 392Total Fat: 34gSaturated Fat: 18gTrans Fat: 1gUnsaturated Fat: 13gCholesterol: 150mgSodium: 812mgCarbohydrates: 6gFiber: 1gSugar: 4gProtein: 16g

This low carb Zucchini Casserole recipe turns an ordinary vegetable into a cheesy, garlicky side dish. It’s a must-try for your dinner menu, whether you eat keto or not!

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