Sunday Baked Vegetable Casserole

Name: Sunday Baked Vegetable Casserole
Prep time: 15 min
Cook time: 45 min
Total time: 1 h
Yield: 6 servings
Ingredients: 3 cups mixed seasonal vegetables (zucchini, bell peppers, carrots); 1 cup chopped spinach; 1 medium onion, diced; 2 cups marinara sauce; 1 teaspoon dried Italian herbs; Salt and pepper to taste; 2 cups shredded mozzarella cheese; 1 cup breadcrumbs

Highlighted under: Dessert Magic

I love nothing more than gathering around the table on a Sunday with a hearty dish that warms the soul. Our Sunday Baked Vegetable Casserole is one of those recipes that has become a beloved staple in our household. The combination of seasonal vegetables and a deliciously seasoned sauce creates a comforting meal that pleases everyone at the table. It’s not just easy to prepare, but it also allows for a bit of creativity as you can mix and match your favorite vegetables. I can’t wait for you to try it!

Created by

Harriet Mason

Last updated on 2026-01-13T22:40:11.661Z

When I first made this casserole, I was blown away by how simple yet flavorful it turned out. It started as a way to use up leftover vegetables from the week, and I was thrilled with the way the flavors melded together. The key to achieving that perfect consistency is to let it bake until the top is golden brown and the vegetables are tender. I recommend checking the casserole a few minutes before it’s done to avoid overcooking.

I've since adapted the recipe a few times, trying different sauces and spices. One variation I particularly loved was adding a sprinkle of smoked paprika for a subtle kick. It’s incredible how small changes can elevate your dish. I encourage you to experiment with your favorite ingredients!

Why You'll Love This Recipe
A medley of colorful, roasted vegetables for a vibrant presentation
Creamy layers that balance the flavors beautifully
Perfect for meal prepping or serving at family gatherings

Selecting the Right Vegetables

Choosing a variety of seasonal vegetables is key to achieving a vibrant and flavorful casserole. Ideal options include zucchini, bell peppers, and carrots, but feel free to experiment with broccoli, eggplant, or even kale. The goal is to mix textures—crunchy and tender alike—so aim for balance. Cutting your vegetables into uniform pieces of about 1-inch ensures even cooking and a cohesive mouthfeel. If you're short on time, pre-chopped vegetables can be a great shortcut, just ensure they are fresh to maintain flavor.

When it comes to the spinach, opt for fresh over frozen for the best taste and texture in this dish. Fresh spinach will wilt beautifully during baking, adding a nice layer of flavor without excess moisture that frozen spinach can sometimes bring. Remember to wash and dry the spinach thoroughly to avoid any watery surprises in your casserole.

Perfecting Your Sauce

The marinara sauce you choose can elevate your casserole significantly. A store-bought organic marinara can save time, but don't hesitate to jazz it up with additional herbs, crushed garlic, or even a splash of red wine for depth. Simmering the added ingredients together for about 10 minutes can meld the flavors beautifully, creating a rich base that seeps into the vegetables, enhancing their natural sweetness.

To ensure a creamy texture, I recommend layering the sauce evenly. This method not only helps in locking moisture within the vegetables but also prevents the cheese from browning too quickly. A crucial tip: keep a small amount of sauce aside to drizzle before serving for added flavor and visual appeal.

Storing and Reheating

If you find yourself with leftovers, storing the baked vegetable casserole is incredibly straightforward. Allow it to cool completely before covering it with foil or transferring it to an airtight container. It can be stored in the fridge for up to 4 days. For longer storage, consider freezing portions in freezer-safe containers. It’s best to separate individual servings to reheat only what you need later on.

When you're ready to enjoy your casserole again, reheating is easy. Preheat your oven to 350°F (175°C) and cover the dish with foil to prevent over-browning. Heat for about 30 minutes until it’s warmed through. Alternatively, you can microwave a single serving covered with a damp paper towel for about 2-3 minutes, checking at the halfway mark to ensure even heating. This method keeps it moist and delicious.

Ingredients

Casserole Ingredients

3 cups mixed seasonal vegetables (zucchini, bell peppers, carrots)
1 cup chopped spinach
1 medium onion, diced
2 cups marinara sauce
1 teaspoon dried Italian herbs
Salt and pepper to taste
2 cups shredded mozzarella cheese
1 cup breadcrumbs

Adjust the ingredients based on your personal preferences! Add or substitute any vegetables you enjoy.

Instructions

Preheat and Prepare

Preheat your oven to 375°F (190°C). In a large bowl, combine the mixed vegetables, spinach, and onion. Season with salt, pepper, and Italian herbs.

Layer the Casserole

Spread half of the vegetable mixture in a greased casserole dish. Pour half of the marinara sauce over the vegetables. Repeat with remaining vegetables and sauce. Top with mozzarella cheese and breadcrumbs.

Bake

Cover the dish with aluminum foil and bake for 30 minutes. Remove the foil and bake for an additional 15 minutes, or until the cheese is bubbly and golden.

Let the casserole cool for a few minutes before serving. It will be hot!

Pro Tips

Feel free to customize the recipe with whatever vegetables you have on hand. Roasted vegetables work particularly well, and you can also add cooked grains for extra heartiness.

Serving Suggestions

Pairing this casserole with a crisp green salad can lighten the meal and add freshness to balance the richness of the cheese. For a comforting twist, consider serving it with a side of crusty garlic bread, making it a truly satisfying Sunday feast. Additionally, a sprinkle of fresh herbs like basil or parsley right before serving not only adds flair but also brings a lively aromatic note to the dish.

For those looking to create a more substantial meal, serving the casserole alongside a protein such as grilled chicken or baked salmon complements the flavors beautifully. The combination of hearty vegetables with a protein boost makes it great for families or gatherings where everyone has different dietary preferences.

Dietary Adjustments

If you're aiming for a dairy-free version, swapping mozzarella for a plant-based cheese is a fantastic option. Many brands offer dairy-free cheeses that melt well and maintain creamy textures. You can also substitute nutritional yeast for cheese to bring in a cheesy flavor without the dairy. Check ingredient labels to avoid any allergens, especially if cooking for a crowd with varied dietary needs.

For those seeking a low-carb alternative, consider using cauliflower rice instead of breadcrumbs on top. This swap not only cuts down on carbs but adds another delicious vegetable to the dish. I recommend pulsing cauliflower in a food processor for a fine texture, then sautéing briefly to remove excess moisture before layering it over your casserole.

Questions About Recipes

→ Can I make this casserole ahead of time?

Yes! You can prepare the casserole and refrigerate it before baking. Just add a few extra minutes to the cooking time if baking from cold.

→ What kind of cheese works best for this recipe?

Mozzarella is great for its melt factor, but feel free to mix in cheddar or a sprinkle of parmesan for additional flavor.

→ Can I freeze leftover casserole?

Absolutely! Just ensure it’s cooled completely before transferring to an airtight container. When ready to eat, thaw overnight in the refrigerator and reheat in the oven.

→ What can I serve alongside this casserole?

A simple green salad or crusty bread pairs beautifully with this hearty dish.