Healthy Zucchini Tomato Casserole – Zucchini Tomato Onion Casserole

Healthy Zucchini Tomato Casserole includes a menagerie of fresh garden veggies sautéed together. Before serving this zucchini, tomato and onion casserole, a layer of shredded Parmesan cheese is melted over top for the perfect finishing touch.

Healthy Zucchini Tomato Casserole Recipe

It’s simple to eat healthier during the summer when garden vegetables are fresh and bountiful. I love combining all that I have in the vegetable drawer and making a tasty garden veggie casserole, which is exactly what drew me into this recipe from my North Carolina Elks Association cookbook.

• Zucchini
• Tomatoes
• Green Peppers
• Red Onion

All these veggies get sautéed in butter, seasoned with salt and black pepper, and then topped with Parmesan cheese before being finished off in the oven.  When the casserole is bubbling, the vegetables are lightly browned, the cheese is melted, and the kitchen smells heavenly, you’ll know these sautéed Parmesan vegetables are ready to eat.

Zucchini Tomato Onion Casserole

Fresh, garden tomatoes tend to be juicy which result in a delightful saucy zucchini tomato onion casserole. I recommend grabbing some bread and butter and sopping up that juice. (This is exactly how our Grandpa would have eaten it). Or, try serving it over cooked rice which also absorbs the tasty sauce.

But, if you prefer less saucy tomato, onions and zucchini, then go ahead and peel and de-seed the tomatoes before adding to the skillet.

If you have an abundance of tomatoes, try these Broiled Tomato Slices!

Ingredient List for Garden Casserole

Green Peppers, sliced

Onions, diced

Butter

Tomatoes, cut into wedges

Salt

Black Pepper

Parmesan Cheese, shredded

How to Make Zucchini, Tomato and Onion Recipe:

1. Sauté green peppers and onions in butter until just softened.
2. Add diced zucchini, and sauté for 5 minutes.
3. To the skillet, add tomato wedges, and continue to cook for 5 minutes or until tomatoes are soft.
4. Season generously with black pepper and salt.
5. Pour into a greased baking dish. Top with shredded Parmesan cheese.
6. Bake in a preheated 375 degree F oven for 15-20 minutes or until the top browns and the cheese melts.
7. Let sit for 10 minutes before serving.

For the full recipe steps and ingredient amounts for Sautéed Zucchini and Tomatoes, scroll to the bottom of this post. 

Notes About Healthy Zucchini Tomato Casserole:

• Substitute white or yellow onions for purple, if desired.
• Use olive oil to sauté your veggies instead of butter if you wish.
• If you are looking for a really cheesy zucchini tomato casserole, add extra Parmesan cheese!
• Be sure to let the zucchini casserole sit on the counter for 10 minutes before serving to let it cool and thicken slightly.
• The original recipe calls for the tomatoes to be peeled. If you prefer to go this route, go for it!
• Want a stove top version with chicken? Try our Chicken with Tomatoes and Zucchini recipe.
• I like the extra liquid in this zucchini onion and tomato bake; however, you can remove the seeds and liquid from the tomato before sautéing. This will result in a thicker casserole.
  • I like to sop up the extra juices with a piece of bread and butter, just like Grandpa would do.  Or, sometimes I serve over cooked rice.

More Zucchini Casserole Recipes:

Old Fashioned Cheesy Zucchini Casserole

Zucchini with Tomatoes and Bacon

Sour Cream Zucchini Casserole

Layered Zucchini Casserole with Ground Beef

Breakfast Casserole with Zucchini