Sunday Baked Vegetable Casserole

Name: Sunday Baked Vegetable Casserole
Prep time: 20 min
Cook time: 45 min
Total time: 1 h 5 min
Yield: 6 servings
Ingredients: 2 cups diced zucchini; 2 cups diced bell peppers (any color); 1 cup chopped onions; 2 cups chopped spinach; 2 cups cherry tomatoes, halved; 4 cups cooked quinoa; 1 cup shredded cheese (cheddar or mozzarella); 1 cup vegetable broth; 2 cloves garlic, minced; 1 teaspoon dried oregano; 1 teaspoon salt; 1/2 teaspoon black pepper; 1 tablespoon olive oil; 1/2 cup breadcrumbs

Highlighted under: Baking & Desserts

I absolutely love making this Sunday Baked Vegetable Casserole for my family. It's a comforting dish that not only tastes amazing but is also packed with colorful vegetables. Every time I prepare it, I enjoy experimenting with different seasonal produce and spices to keep it fresh and exciting. The warm, savory flavors combined with a crispy topping create a perfect harmony, making it a favorite at our Sunday dinner table. Trust me, once you try this dish, it will become a staple in your home too!

Created by

Celeste Morgan

Last updated on 2026-01-13T23:10:20.522Z

When I first attempted to make this casserole, I was challenged by the idea of blending so many vegetables into one dish without losing their individual flavors. I found that layering them not only preserved their distinct tastes but also added to the visual appeal of the meal. Using fresh herbs and a squeeze of lemon juice right before serving elevates the entire dish!

Throughout the years, I have refined my method, ensuring a perfect balance of creaminess and crunch in each bite. Adding a dash of smoked paprika gives it a surprising depth of flavor that everyone seems to love. This is one wonderfully satisfying recipe that I’m proud to serve!

        Why You'll Love This Recipe
        Loaded with nutritious and colorful vegetables
Comforting, warm, and perfect for family gatherings
Easily customizable with your favorite seasonal produce

      

Choosing the Right Vegetables

The beauty of the Sunday Baked Vegetable Casserole lies in its versatility. You can use any combination of seasonal vegetables, and the flavor will remain vibrant and delicious. If you have leftover roasted vegetables, feel free to toss them into the mix. Just make sure that whatever vegetables you choose, they are cut uniformly to ensure even cooking. For example, diced eggplant or chopped kale could also work wonderfully in this dish.

When selecting your veggies, look for those that have a similar cooking time. Dense vegetables like carrots or potatoes may need a little extra time to cook through, so it's best to either precook them or opt for quicker-cooking options. Also, be sure to wash and dry them well before cutting to avoid excess moisture in your casserole, which can make the dish soggy.

Cheese and Topping Options

The cheese plays a crucial role in this casserole, both for flavor and texture. While cheddar or mozzarella are classic choices, consider experimenting with different cheeses like feta for a tangy twist or gouda for a richer flavor. You can also use dairy-free cheese alternatives if you're looking to make this dish vegan-friendly; just ensure they melt well for that perfect gooey texture.

The topping adds an essential crunch that contrasts beautifully with the soft baked vegetables. If you prefer a healthier option, you can replace traditional breadcrumbs with crushed nuts like almonds or pecans, which will provide a nice crunch and additional protein. A sprinkle of nutritional yeast can also enhance the cheesy flavor without any dairy. Baking until the top is golden brown gives you a lovely crispy finish.

Make-Ahead and Storage Tips

One of the best features of this casserole is its make-ahead potential. You can prepare it a day in advance by assembling the casserole and covering it tightly in the refrigerator. When you're ready to bake, just pop it into the oven, adding a few extra minutes to the baking time if it's going straight from the fridge. This makes it an excellent option for busy weekends or potlucks.

If you have leftovers, store them in an airtight container in the fridge for up to three days. You can also freeze individual portions for quick and healthy meals later on. Just ensure the casserole is completely cooled before freezing, and wrap it tightly in plastic wrap and aluminum foil to avoid freezer burn. To reheat, thaw overnight in the fridge and bake until heated through. This method maintains the casserole's texture and flavor beautifully.

Ingredients

Vegetable Casserole Ingredients

2 cups diced zucchini
2 cups diced bell peppers (any color)
1 cup chopped onions
2 cups chopped spinach
2 cups cherry tomatoes, halved
4 cups cooked quinoa
1 cup shredded cheese (cheddar or mozzarella)
1 cup vegetable broth
2 cloves garlic, minced
1 teaspoon dried oregano
1 teaspoon salt
1/2 teaspoon black pepper
1 tablespoon olive oil
1/2 cup breadcrumbs

Feel free to mix and match your favorite vegetables in this casserole!

Instructions

Preheat the Oven

Preheat your oven to 375°F (190°C) and lightly grease a large baking dish.

Sauté the Vegetables

In a large skillet, heat the olive oil over medium heat. Add the onions and garlic, sautéing until they are translucent. Then, add the zucchini, bell peppers, spinach, and cook for about 5 minutes until they start to soften.

Combine Ingredients

In a large mixing bowl, combine the sautéed vegetables, cooked quinoa, vegetable broth, oregano, salt, and pepper. Mix in half of the shredded cheese.

Bake the Casserole

Pour the vegetable mixture into the prepared baking dish. Top with the remaining cheese and breadcrumbs. Bake for 30-35 minutes or until the casserole is bubbly and golden on top.

Serve and Enjoy

Let the casserole cool for a few minutes before serving. Enjoy this flavorful and nutritious dish with your loved ones!

This casserole can be stored in the refrigerator for up to three days.

Pro Tips

For an extra flavor kick, try adding some sliced olives or artichokes to the mixture!

Serving Suggestions

This casserole makes a hearty main dish, but it also pairs excellently with a light salad or crusty bread for a more rounded meal. Try serving it alongside a simple arugula salad with a lemon vinaigrette to balance the richness of the cheese. It also works well with a side of roasted veggies for an extra serving of nutrition, ensuring your meal feels vibrant and colorful.

For a flavor boost, consider drizzling a bit of balsamic glaze over the top just before serving. This adds a sweet-tangy contrast that complements the savory nature of the casserole beautifully. If you’re hosting friends or family, presenting it with a selection of dips, like hummus or tzatziki, can add to a fun, communal dining experience.

Customization Ideas

Feel free to customize this casserole based on your dietary needs or preferences. For a protein boost, you can add cooked lentils, beans, or even shredded chicken for a heartier option. If you're aiming for a low-carb dish, substitute quinoa with cauliflower rice or another vegetable-based alternative that enhances the flavor without the extra carbs.

If you’re a spice lover, try adding some crushed red pepper flakes or diced jalapeños to the sautéed vegetables for a kick of heat. You can also experiment with different herbs and spices, like thyme or rosemary, to impart unique flavors to the dish. The idea is to make this casserole your own, so have fun in the kitchen!

Common Troubleshooting Tips

If you find that your casserole is coming out too watery, it might be a sign that you added too many high-water-content vegetables like zucchini or tomatoes. To remedy this, try pre-cooking these vegetables by sautéing them until their moisture evaporates before adding them to the casserole. Another option is to use a thicker vegetable broth or reduce the amount of broth used to allow the other ingredients to shine without becoming soggy.

On the other hand, if your casserole is coming out too dry, it could benefit from a sprinkle of water or additional vegetable broth before baking. During the baking process, keeping it covered for part of the time can help retain moisture. Additionally, be sure to monitor the cheese's browning—if it's getting too dark, cover it with foil until the casserole is fully heated through.

Questions About Recipes

→ Can I use frozen vegetables?

Yes, frozen vegetables work great in this casserole. Just ensure they are thawed and drained before adding.

→ How can I make this recipe gluten-free?

Simply use gluten-free breadcrumbs and ensure your vegetable broth is gluten-free.

→ Can I prepare this ahead of time?

Absolutely! You can prepare the casserole up to 24 hours in advance and store it in the refrigerator before baking.

→ What can I substitute for cheese?

You can swap cheese with nutritional yeast for a dairy-free option or simply omit it for a lighter version.