Sunday Baked Vegetable Casserole

Name: Sunday Baked Vegetable Casserole
Prep time: 20 min
Cook time: 40 min
Total time: 1 h
Yield: 6 servings
Ingredients: 2 cups chopped zucchini; 1 cup chopped bell peppers (red and yellow); 1 cup chopped mushrooms; 1 cup corn kernels (fresh or frozen); 2 cups cooked quinoa or rice; 1 cup shredded sharp cheddar cheese; 1 cup shredded mozzarella cheese; 1/2 cup grated Parmesan cheese; 2 cups marinara sauce; 2 tablespoons olive oil; 1 teaspoon dried oregano; 1 teaspoon dried basil; Salt and pepper to taste; Fresh parsley for garnish

Highlighted under: Baking & Desserts

I love making this Sunday Baked Vegetable Casserole, especially when I'm looking for a hearty yet healthy dish that the whole family will enjoy. It's packed with seasonal vegetables, and the gooey cheese on top creates a wonderful contrast to the tender veggies beneath. This casserole is not only a great way to use up leftovers, but it's also a delightful centerpiece for a cozy family dinner. Plus, it warms up beautifully, making for perfect leftovers during the week.

Created by

Keira Dalton

Last updated on 2026-01-13T22:01:05.118Z

When I first crafted this Sunday Baked Vegetable Casserole, I wanted to create a dish that highlighted the vibrant colors and flavors of fresh vegetables. I've experimented with different cheese combinations, but I find that a mix of sharp cheddar and mozzarella gives the best melty texture and flavor. One tip that I've discovered is to slightly undercook the vegetables before baking; they maintain their shape and don’t get mushy.

As I bake this casserole, the aroma fills my kitchen and creates such an inviting atmosphere. It’s the perfect side dish for any meal, but I find it especially comforting to serve on Sundays. I love how you can customize it with whatever vegetables are in season, making it versatile and fun to make with my family.

        Why You'll Love This Recipe
        Packed with vibrant, seasonal vegetables
Cheesy goodness that brings everyone together
Perfect for meal prep or a cozy family dinner

      

Choosing the Right Vegetables

One of the joys of making this Sunday Baked Vegetable Casserole is the freedom to use whatever seasonal vegetables you have on hand. Zucchini, bell peppers, and mushrooms are excellent choices due to their ability to soften and meld with the other ingredients while providing great flavor. You can also substitute vegetables like eggplant, spinach, or even roasted butternut squash if you want an extra layer of sweetness. Just be sure to adjust the cooking time slightly for denser vegetables.

When selecting your bell peppers, aim for firm ones with a vibrant color, as they not only add visual appeal but also richer sweetness to the dish. Fresh corn brings a delightful crunch, but if you're in a pinch, frozen corn works just as well and can be added directly without thawing. Each vegetable contributes its unique texture and taste, enhancing the overall harmony of the casserole.

Cheese Selection and Layering

Cheese is a crucial component of this casserole, adding a rich, gooey texture that complements the tender vegetables. While sharp cheddar, mozzarella, and Parmesan create a lovely flavor profile, don't hesitate to experiment with your favorites. For a sharper bite, consider adding some crumbled feta or goat cheese. If you're aiming for a lower-fat version, you can use part-skim cheese options, ensuring you still achieve that creamy texture but with fewer calories.

As you layer the cheeses on top, be generous but even. A good rule of thumb is to distribute the cheeses in two layers—one mixed into the vegetable mixture before baking and the other sprinkled on top. This method creates a delicious cheesy crust while preventing the bottom of the casserole from becoming overly dry.

Ingredients

Gather these fresh ingredients to make your casserole shine:

Ingredients

2 cups chopped zucchini
1 cup chopped bell peppers (red and yellow)
1 cup chopped mushrooms
1 cup corn kernels (fresh or frozen)
2 cups cooked quinoa or rice
1 cup shredded sharp cheddar cheese
1 cup shredded mozzarella cheese
1/2 cup grated Parmesan cheese
2 cups marinara sauce
2 tablespoons olive oil
1 teaspoon dried oregano
1 teaspoon dried basil
Salt and pepper to taste
Fresh parsley for garnish

Make sure you have all these ingredients prepped before starting your casserole!

Instructions

Follow these steps to create a delicious casserole:

Preheat the Oven

Preheat your oven to 375°F (190°C).

Sauté the Vegetables

In a large skillet, heat the olive oil over medium heat. Add the zucchini, bell peppers, and mushrooms. Sauté for about 5-7 minutes until the vegetables start to soften.

Mix Ingredients

In a large bowl, combine the sautéed vegetables, corn, quinoa (or rice), marinara sauce, oregano, and basil. Season with salt and pepper to taste.

Assemble the Casserole

Transfer the mixture to a greased baking dish. Sprinkle the cheddar, mozzarella, and Parmesan cheese evenly on top.

Bake

Cover the dish with aluminum foil and bake for 25 minutes. Remove the foil and bake for an additional 15 minutes, or until the cheese is golden and bubbly.

Garnish and Serve

Let the casserole cool for a few minutes before garnishing with fresh parsley. Serve warm and enjoy!

Serving this casserole is a treat, and leftovers are even better the next day!

Pro Tips

Feel free to swap in any vegetables you have on hand, such as spinach or broccoli. This recipe is very forgiving and allows for creative additions!

Make-Ahead Tips

This casserole is an excellent make-ahead option for busy weeks. You can prepare the entire dish the day before, covering it tightly with plastic wrap or aluminum foil, and store it in the refrigerator. Before you're ready to serve, settle it out on the counter for about 30 minutes to help it warm up slightly. Bake it as directed, adding an extra 5-10 minutes to the cooking time since it will start cold from the fridge.

If you're looking to freeze the casserole, it's best to freeze it before baking. Assemble it in a freezer-safe dish and cover tightly with foil. When you're ready to bake it, let it thaw in the refrigerator overnight and then proceed with baking. Freezing helps lock in the flavors, making it an easy meal solution for stressed nights.

Serving Suggestions

This baked vegetable casserole can stand alone as a fulfilling meal, but pairing it with a simple side salad will elevate your dining experience. A crisp salad dressed in a light vinaigrette complements the rich flavors of the casserole beautifully. Try adding some nuts or seeds for texture and additional nutrition.

For a fun twist, consider serving the casserole with homemade garlic bread or a scoop of creamy mashed potatoes on the side. Not only does this add variety to your table, but it also allows family and guests to customize their meals according to personal tastes, making for a cozy and interactive dinner experience.

Questions About Recipes

→ Can I make this casserole ahead of time?

Absolutely! You can prepare the casserole a day in advance and keep it refrigerated. Just bake it right before serving.

→ Is it possible to freeze the casserole?

Yes, you can freeze the casserole before baking. Make sure to thaw it in the fridge overnight before baking.

→ What can I serve with this casserole?

This dish pairs wonderfully with a fresh salad or crusty bread.

→ Can I make this dish vegan?

Yes! You can use plant-based cheeses and substitute the quinoa or rice with more vegetables.