This is the best vegetable casserole recipe! Made with fresh vegetables and a sprinkling of cheese, this casserole bakes in just 30 minutes. It's quick, easy, and so delicious!

Why This Recipe Works
This fresh and flavorful vegetable casserole is the perfect way to use the season's freshest produce. The recipe can be easily customized so that you can use vegetables you have on hand. In this particular version, we've used zucchini, red pepper, onions, and broccoli - a wonderful combination!
The vegetables are tossed in olive oil, seasonings, shredded cheese and baked in the oven. Within minutes you're able to enjoy a healthy, hearty, single serving meal.
I think you'll find this vegetable casserole to be a little like a ratatouille and it's a great way to use your summer bounty of produce. It's low carb, vegetarian, and can be vegan if you use a vegan cheese or leave the cheese out altogether.
Ingredient Notes
See recipe box below for ingredient amounts and full recipe instructions.
- Olive oil: I use extra virgin olive oil in this vegetable casserole recipe as well as in every other recipe on One Dish Kitchen that calls for olive oil. Extra virgin olive oil is the least processed form of olive oil. It is an unrefined oil and the highest-quality olive oil you can buy. Because of the way extra virgin olive oil is made, it retains more true olive taste. It also contains more of the vitamins and minerals found in olives. It's my favorite type of olive oil to use but you may use a lighter olive oil instead.
- Vegetables: I used zucchini, red pepper, broccoli florets, and onions. Feel free to use vegetables that are in season or ones you have on hand.
- Seasonings: I love using herbes de Provence or Italian seasoning in this recipe along with a little salt and black pepper.
- Cheese: I recommend using monterey jack cheese. You can use cheddar, gouda, or your favorite cheese instead.
See below for ways to use any leftover ingredients.

Frequently Asked Questions
I love using herbs de Provence in so many recipes. It's a wonderful spice to keep on hand and I think you will find it to be very versatile. It is a spice blend made with many spices found in the southeastern region of France. It is an essential spice found in many French and Mediterranean dishes.
This aromatic spice usually contains a combination of dried thyme, oregano, rosemary, marjoram, parsley, and lavender flowers. It's an all-purpose seasoning that is especially delicious when used with chicken, turkey and seafood.
If you don't have any herbs de Provence on hand, feel free to substitute Italian seasoning, dried rosemary, dried thyme, dried oregano, or any combination of these spices in this vegetable casserole recipe.
You sure can. Frozen vegetables work great in this recipe, just be sure to thaw them first.
A simple vegetable casserole is a great recipe to prep the day before. Mix the vegetables together and toss them in the oil, spices and cheese, then refrigerate. When you're ready to enjoy the casserole, take the pre-mixed veggies out of the oven and bake it.
How To Make This Recipe
- Place the sliced vegetables in a medium-sized bowl. Toss with olive oil, salt, pepper, and spices.

- Stir in the cheese.

- Lightly grease the bottom and sides of a small baking dish with olive oil. Pour the seasoned vegetables in the baking dish. Bake in a preheated 350 degrees F (177 degrees C) oven for 30 minutes.

Ways To Use Leftover Ingredients
If you have any ingredients left over from this vegetable casserole recipe you might like to consider using them in any of these single serving and small batch recipes:
- Zucchini: Mini Zucchini Lasagna, Zucchini Noodles with Shrimp, Vegetarian Enchiladas
- Red peppers: Chicken Chili, Cucumber Salsa, Healthy Sloppy Joe
- Onions: French Onion Soup, Rice Pilaf, Meat Sauce
- Broccoli: Broccoli Cheese Soup, Cashew Chicken, Italian Pasta Salad
- Herbs de Provence: Pasta with Roasted Vegetables, Croutons
- Monterey Jack Cheese: Enchiladas Verdes, Breakfast Casserole
Expert Tips
- Feel free to use vegetables that are in season or ones you have on hand.
- Instead of using monterey jack cheese, feel free to a different kind of cheese like smoked gouda or havarti.

Vegetable Casserole Topping
Many vegetable casseroles are made with a crusty, buttery topping. I like to keep my version low in carbs but you could absolutely make a glorious topping to add to your own casserole if you'd like.
Ingredients
- 3 tablespoons seasoned bread crumbs
- 2 tablespoons butter, melted
Instructions
In a small bowl, mix together the bread crumbs and the melted butter. Sprinkle over top of vegetable casserole. Bake as directed in the recipe.
Serving Suggestions
Products Used In This Recipe
For this vegetable casserole, I use a 5-inch baking dish which you can find on our store page. This dish holds about 1.5 cups and has an area of 25 square inches. A 4×6-inch dish has an area of 24 square inches and will work as well. For best results, use a dish of similar size. See our FAQ page for additional information on baking dish sizes.
I also recommend investing in a small kitchen food scale. A scale is the most accurate way to measure ingredients for a recipe. Produce sizes vary so I've included in the recipe the number of ounces of each vegetable used. If you do not have a scale to measure, I've also listed the size of the vegetable used.
For examples of the dishes we use, please visit our Store page.
If you’ve tried this vegetable casserole or any recipe on One Dish Kitchen please let me know how you liked it by rating the recipe and telling me about it in the comment section below.
If you take a picture please tag us on Instagram (@onedishkitchen) we’d love to see!

Ingredients
- 3 tablespoons olive oil , divided
- 1 small zucchini, sliced (3 ounces sliced zucchini)
- ½ small red pepper, sliced (3 ounces sliced red peppers)
- ¼ small onion, sliced (2 ounces sliced onions)
- ½ cup broccoli florets (2 ounces broccoli florets)
- ½ teaspoon herbs de Provence
- ¼ teaspoon kosher salt
- ⅛ teaspoon coarsely ground black pepper
- 1/4 cup shredded Monterey Jack cheese (1 ounce shredded cheese)
Instructions
- Heat oven to 350° F (177° C). Spread 1 tablespoon of olive oil on the bottom of a small 5-inch baking dish. Set aside.
- Place the sliced zucchini, red peppers, onions, and broccoli in a small bowl. Toss the vegetables with the remaining olive oil, the herbs de Provence, salt, and pepper. Stir in the shredded cheese.
- Pour the seasoned vegetables into the prepared baking dish. Bake for 30 minutes.
- Enjoy warm.
Notes
- Feel free to use vegetables that are in season or ones you have on hand.
- Instead of using monterey jack cheese, feel free to a different kind of cheese like smoked gouda or havarti.
Nutrition
The information shown is an estimate provided by an online nutrition calculator. It should not be considered a substitute for a professional nutritionist’s advice.
Great recipe! I added some left over sautéed mushrooms & onions (I don’t like peppers so I left them out) and should have reduced the oil to compensate for the “extra” oil in them, but the flavors are great and I’ll make this again, maybe even tonight! There was too much butter in the topping but honestly I will adjust that anyway to add a little parm.
I’m so glad you enjoyed the casserole. Thank you so much for your feedback.
I made this last night and loved it, added garlic because everything is better with garlic.
I’m so happy you enjoyed the recipe. I’m with you on the garlic, it’s always a good idea. Thanks so much for your feedback.
I just made the this with vegetables a herb and cheese I had on hand. I hope it tastes at good as it smells
The recipe description says to coat the sides and bottom of the baking dish with oil, but in the recipe itself, it says to pour a tablespoon into the bottom of the dish and set aside. Also, the recipe itself does not mention what to do with the other two tablespoons of oil. I assume they are tossed with the veggies and seasoning. I’m baking the casserole right now, and I’m excited to taste it!
Hi Lynn, I hope you enjoyed the casserole. Yes, the remaining oil is tossed with the vegetables.
It does say to toss the remaining oil with the veggies. But I noticed what you said about coating the sides and bottom with oil vs. pour one tablespoon of oil in the dish.
Love veggie casseroles, this one is just perfect!
Thank you, Billie.