Sunday Baked Vegetable Casserole

Highlighted under: Baking & Desserts

I love a good vegetable casserole, especially when it brings all my favorite Sunday ingredients together. This Sunday Baked Vegetable Casserole isn't just a dish; it's a celebration of colors and flavors that come together beautifully. Packed with various vegetables, fresh herbs, and a gooey cheese topping, it's the perfect comfort food for a family gathering. The best part? It’s easy to prepare ahead of time, and everyone always goes back for seconds. Trust me; once you try this recipe, it will become a weekly favorite!

Adele Summers

Created by

Adele Summers

Last updated on 2026-01-13T21:16:19.356Z

During one of my Sunday family get-togethers, I decided to impress everyone with a hearty vegetable casserole. I layered fresh zucchini, bell peppers, and spinach with cheese, and the aroma wafting through the house was simply irresistible. What made it truly special was the hint of thyme and freshly grated Parmesan, giving it an aromatic punch.

The moment I pulled it from the oven, the bubbly, golden crust had everyone clamoring at the table. I realized then that a great casserole is about layering flavors and letting them shine together. I particularly love preparing it the night before and allowing the flavors to meld overnight—trust me, it makes all the difference!

Why You'll Love This Recipe

  • A vibrant medley of seasonal vegetables
  • Rich, gooey cheese that complements the veggies
  • Easy to prepare ahead, perfect for gatherings

Vegetable Choices and Flavor Balance

The combination of vegetables in this casserole not only creates a delightful texture but also an appealing presentation. Zucchini and bell peppers offer a crunchy bite, while spinach introduces a tender, leafy element. Each vegetable releases its unique flavors as they cook, resulting in a rich, savory base. When selecting vegetables, consider using seasonal options for the freshest taste. For example, you can substitute asparagus for zucchini in the spring or add roasted butternut squash in the fall for a touch of sweetness.

One common mistake is overcooking the vegetables during the sautéing process. You want to soften them enough to blend flavors without losing their structure. Sauté just until they start to soften—about 5 minutes—then add the spinach, which wilts quickly. This technique preserves the vibrant colors and crunch, ensuring each bite remains satisfying.

Cheese Selection and Layering Techniques

The cheeses you choose can drastically affect the flavor and texture of the casserole. Mozzarella provides that gooey, stretchy quality everyone loves, while the Parmesan adds a sharp, nutty flavor that enhances the overall profile. If you're looking for a lower-fat option, consider using part-skim mozzarella or a cheese blend. However, be careful to choose cheeses that melt well to avoid a grainy texture.

When layering the casserole, spread the sautéed vegetables evenly to ensure every serving has a balance of flavors. Start with a base layer of the veggie mix, then top it with the halved cherry tomatoes—this not only adds a burst of sweetness but also creates an appealing visual layer of color. Sprinkle the mozzarella and Parmesan uniformly, making sure every corner of the dish gets its cheesy goodness.

Make-Ahead Options and Reheating Tips

This casserole shines as a make-ahead dish, ideal for busy families. You can prepare it a day in advance, assembling the layers and covering the dish with foil before refrigerating. When you’re ready to bake, simply add an extra 5-10 minutes to the cooking time if going directly from the fridge. This make-ahead strategy not only saves time but allows the flavors to meld together beautifully, enhancing the dish's richness.

Storing leftovers is easy, too! Just let any remaining casserole cool completely before transferring it to an airtight container. It can last in the fridge for up to 4 days, or you can freeze it for up to 3 months. To reheat, thaw in the refrigerator overnight and bake in a preheated oven at 350°F (175°C) until heated through—about 20-30 minutes. If you're reheating from frozen, you may need to bake it for an additional 10-15 minutes.

Ingredients

Vegetable Ingredients

  • 2 cups diced zucchini
  • 1 cup chopped bell peppers (any color)
  • 1 cup chopped spinach
  • 1 cup sliced mushrooms
  • 1 cup cherry tomatoes, halved
  • 1 small onion, chopped
  • 2 cloves garlic, minced

Casserole Topping

  • 2 cups shredded mozzarella cheese
  • 1/2 cup grated Parmesan cheese
  • 1 teaspoon dried thyme
  • Salt and pepper to taste

Steps

Prepare the Vegetables

In a large skillet over medium heat, add a splash of olive oil and sauté the onion and garlic until fragrant. Add the zucchini, bell peppers, and mushrooms, and cook for about 5 minutes, until softened. Stir in the spinach until wilted and season with salt, pepper, and thyme.

Layer the Casserole

Preheat your oven to 375°F (190°C). In a large baking dish, layer the sautéed vegetables evenly. Scatter the halved cherry tomatoes on top and sprinkle a generous layer of mozzarella cheese followed by Parmesan.

Bake

Cover the dish with foil and bake for 20 minutes. Remove the foil and bake for an additional 20 minutes or until the cheese is golden brown and bubbly. Let it sit for a few minutes before serving.

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Pro Tips

  • For an added crunch, consider sprinkling some breadcrumbs on top before baking. This casserole also works well with any seasonal vegetables you have on hand, so feel free to adapt it as needed!

Serving Suggestions

This Sunday Baked Vegetable Casserole is incredibly versatile for serving. Pair it with a fresh green salad to complement the dish's richness, or consider serving it alongside grilled chicken or fish for a complete meal. I love adding a tangy balsamic vinaigrette to the salad to balance the casserole's cheesy comfort with a burst of acidity.

For an extra layer of flavor, incorporate fresh herbs such as basil or parsley just before serving. This fresh touch not only uplifts the dish but also adds a fragrant aroma that entices everyone at the table. You can also serve it with crusty bread for scooping up those cheesy, vegetable bites.

Variations to Try

Feel free to get creative with this recipe by substituting or adding your favorite vegetables. Carrots, broccoli, or even sweet corn can work wonderfully. If you're looking to spice things up, consider adding diced jalapeños or a sprinkle of red pepper flakes before baking for a kick of heat.

Another fun variation is to experiment with different cheese blends. Try using gouda for a smokier flavor or incorporating feta for a salty contrast. Mixing in some cooked quinoa or rice can also stretch the dish further, adding extra heartiness and making it ideal for a potluck gathering.

Questions About Recipes

→ Can I make this casserole ahead of time?

Absolutely! Prepare the casserole the night before, cover it, and refrigerate. Just add an extra 10-15 minutes to the baking time if cooking from cold.

→ What other vegetables can I add?

You can add any seasonal vegetables such as broccoli, carrots, or asparagus. Just ensure you cut everything to similar sizes for even cooking.

→ Is this dish vegan-friendly?

Yes, you can substitute the cheese with a vegan cheese alternative or nutritional yeast for a cheesy flavor without dairy.

→ Can I freeze the leftover casserole?

Yes, you can freeze leftovers in an airtight container for up to 3 months. Reheat in the oven until warmed through.

Sunday Baked Vegetable Casserole

I love a good vegetable casserole, especially when it brings all my favorite Sunday ingredients together. This Sunday Baked Vegetable Casserole isn't just a dish; it's a celebration of colors and flavors that come together beautifully. Packed with various vegetables, fresh herbs, and a gooey cheese topping, it's the perfect comfort food for a family gathering. The best part? It’s easy to prepare ahead of time, and everyone always goes back for seconds. Trust me; once you try this recipe, it will become a weekly favorite!

Prep Time20 minutes
Cooking Duration40 minutes
Overall Time1 hour

Created by: Adele Summers

Recipe Type: Baking & Desserts

Skill Level: Easy

Final Quantity: 8 servings

What You'll Need

Vegetable Ingredients

  1. 2 cups diced zucchini
  2. 1 cup chopped bell peppers (any color)
  3. 1 cup chopped spinach
  4. 1 cup sliced mushrooms
  5. 1 cup cherry tomatoes, halved
  6. 1 small onion, chopped
  7. 2 cloves garlic, minced

Casserole Topping

  1. 2 cups shredded mozzarella cheese
  2. 1/2 cup grated Parmesan cheese
  3. 1 teaspoon dried thyme
  4. Salt and pepper to taste

How-To Steps

Step 01

In a large skillet over medium heat, add a splash of olive oil and sauté the onion and garlic until fragrant. Add the zucchini, bell peppers, and mushrooms, and cook for about 5 minutes, until softened. Stir in the spinach until wilted and season with salt, pepper, and thyme.

Step 02

Preheat your oven to 375°F (190°C). In a large baking dish, layer the sautéed vegetables evenly. Scatter the halved cherry tomatoes on top and sprinkle a generous layer of mozzarella cheese followed by Parmesan.

Step 03

Cover the dish with foil and bake for 20 minutes. Remove the foil and bake for an additional 20 minutes or until the cheese is golden brown and bubbly. Let it sit for a few minutes before serving.

Extra Tips

  1. For an added crunch, consider sprinkling some breadcrumbs on top before baking. This casserole also works well with any seasonal vegetables you have on hand, so feel free to adapt it as needed!

Nutritional Breakdown (Per Serving)

  • Calories: 350 kcal
  • Total Fat: 20g
  • Saturated Fat: 10g
  • Cholesterol: 30mg
  • Sodium: 420mg
  • Total Carbohydrates: 30g
  • Dietary Fiber: 5g
  • Sugars: 6g
  • Protein: 15g