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Zucchini and Pepper Casserole

This zucchini and pepper casserole is perfect for potlucks!  It's made with fresh zucchini, diced red peppers, onion, tomato sauce, and mozzarella cheese.

Summer Casserole

This casserole is perfect for the summertime because of the abundance of summer squash!  This recipe uses four medium-sized zucchini's, making it a great recipe to use those zucchini's without them going to waste! 

Zucchini and Pepper casserole in white dish with a red checkered napkin.


  • zucchini, medium sized
  • butter
  • onion, sliced thin
  • red pepper, diced
  • onion powder
  • oregano
  • salt
  • tomato sauce
  • shredded cheese
  • parsley

Veggies and Cheese

Making this casserole is incredibly easy.  First,  saute the sliced onions, diced red peppers, and sliced zucchini on the stove.  Then, toss with the seasonings and add in the tomato sauce.  After the veggies have softened a bit (about 5 minutes) pour them into a lightly greased 13x9 dish and sprinkle the veggies with mozzarella cheese. 

Related:  Lemon Oven Roasted Asparagus 

Zucchini and pepper casserole in a 13x9 baking dish.

Baking the Casserole

After the baking dish is prepared, place it uncovered in the preheated oven.  My oven takes about 30 minutes to get the cheese nice and bubbly. 

If you want the cheese to crisp a bit, turn on the broiler for about three to five minutes.  Keep an eye on it though so that it doesn't burn!

📖 Recipe

Yield: 8 servings

Zucchini and Pepper Casserole

Zucchini and Pepper Casserole

This zucchini and pepper casserole is perfect for potlucks!  It's made with fresh zucchini, diced red peppers, and tomato sauce.  It's then covered with mozzarella cheese and baked in the oven until the cheese is bubbly. It is then sprinkled with fresh parsley.

Prep Time 10 minutes
Cook Time 30 minutes
Total Time 40 minutes



  1. Preheat oven to 350° F.
  2. In a large skillet, melt the butter and add in the sliced onions and diced red peppers.
  3. Add in the sliced zucchini and sprinkle with the onion powder, salt, and oregano. 
  4. Stir the veggies in the skillet and add in the tomato sauce.
  5. Stir occasionally and heat in a skillet for about 5 minutes on medium-low heat. 
  6. Lightly spray a 13x9 dish and spoon the mixture evenly into the dish.
  7. Sprinkle the dish with the 2 cups of shredded mozzarella cheese.
  8. Bake in the preheated oven for about 30 minutes, or until the cheese is browned and bubbly.
  9. Take out of the oven, and sprinkle with fresh chopped parsley. 
  10. Serve.

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Nutrition Information:



Serving Size:


Amount Per Serving: Calories: 184Total Fat: 14gSaturated Fat: 8gTrans Fat: 0gUnsaturated Fat: 5gCholesterol: 39mgSodium: 440mgCarbohydrates: 7gFiber: 2gSugar: 4gProtein: 8g

Nutrition calculation is a rough estimate and can vary depending on the cooking technique and the exact ingredients used. For informational purposes only.

Did you make this recipe?

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Zucchini and Pepper Casserole 2


Colen Thomas

Sunday 2nd of July 2023

Made this today with a few substitutions for items I did not have. I had a couple of large yellow squash in place of the zucchini and a bunch of leftover green onions in place of the onion. In place of tomato sauce I used diced tomatoes which I ran thru my blender to which I added a little salt , pepper, garlic powder and oregano. Also, I subbed a green bell pepper for the red. Much less expensive and still delicious. Thank you for this recipe. I will make it again. I am an 87 year old man, living alone since the death of the love of my life almost two years ago.


Tuesday 31st of October 2023

@Colen Thomas, Good ideas! Best wishes for healing your heart and finding companionship.

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