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: 2 cups zucchini, sliced; 2 cups bell peppers, diced; 1 cup carrots, diced; 1 cup broccoli florets; 1 cup mushrooms, sliced; 4 tablespoons butter; 4 tablespoons all-purpose flour; 2 cups milk; 1 cup cheddar cheese, grated; 1/2 cup parmesan cheese, grated; Salt and pepper to taste; 1 cup breadcrumbs; 1 tablespoon olive oil; 1 tablespoon fresh parsley, chopped

Highlighted under: Baking & Desserts

I absolutely love Sundays, and what better way to celebrate the weekend than with a comforting baked vegetable casserole? This recipe has become a family favorite because it’s not only easy to prepare, but it also showcases a delightful medley of seasonal vegetables. The blend of creamy cheese and fresh herbs brings everything together, creating a dish that is both hearty and satisfying. I often experiment with whatever veggies I have on hand, making it a versatile and forgiving recipe that's perfect for any lazy Sunday.

Created by

Maribel Hayes

Last updated on 2026-01-13T23:22:22.224Z

When I first decided to experiment with a baked vegetable casserole, I wasn’t sure how it would turn out. I started by roasting my favorite vegetables, and the delicious aroma filled my kitchen. I realized that layering the veggies with a béchamel sauce added richness and creaminess that elevated the dish beyond my expectations.

As I perfected my technique, I discovered that using a mix of fresh herbs not only enhanced the flavors but also added vibrant colors. This casserole has since become a cherished part of my Sunday routine, and I love serving it with a crisp salad for a complete meal.

        Why You'll Love This Casserole
        A delightful medley of seasonal vegetables bursting with flavor
Creamy layers that create a satisfying mouthfeel
Perfect for leftovers or as a make-ahead dish
Easily customizable with your favorite ingredients

      

Choosing the Right Vegetables

The beauty of this baked vegetable casserole lies in its versatility, allowing you to incorporate a variety of seasonal vegetables. Zucchini and bell peppers not only add color but also bring moisture to the dish, preventing it from becoming dry. If you’re aiming for a more earthy flavor, consider substituting mushrooms with roasted eggplant or adding asparagus for a unique twist. Always aim for vegetables that are fresh and at their peak for the most flavor.

Cooking the vegetables slightly before adding them to the casserole is essential. Sautéing enhances the natural sweetness and reduces excess moisture, which can make the casserole soggy. Aim for a tender-crisp texture after about 5 minutes on medium heat. This technique also allows the flavors to meld beautifully, setting the stage for the béchamel sauce and creating a wonderful depth of flavor.

Mastering the Béchamel Sauce

The béchamel sauce is the creamy heart of this casserole; achieving the right consistency is crucial. Start with equal parts butter and flour to form a roux that thickens the milk properly. Make sure to whisk continuously while adding the milk to prevent lumps. If your sauce ends up too thick, a splash of additional milk can help reach the desired creaminess, while a too-thin sauce can be remedied by simmering it a bit longer until it thickens.

Incorporating cheese into the béchamel not only adds flavor but also creates a luxurious texture. Cheddar provides a rich taste, while parmesan gives a subtle nuttiness that elevates the overall dish. Experimenting with half-and-half or a combination of cheeses can also create unique flavors, so feel free to mix things up based on what you have available in your cheese drawer.

Storing and Serving Suggestions

This casserole makes for excellent leftovers. Simply cover it tightly with foil or transfer it to an airtight container and refrigerate for up to 3 days. When you’re ready to enjoy it again, reheat in the oven at 350°F (175°C) until heated through, about 20-25 minutes. To maintain the crunchy topping, consider covering the dish loosely with foil during reheating and removing it for the last 5-10 minutes.

For serving, you can pair this casserole with a light salad to balance the richness of the cheese. A simple vinaigrette can cut through the creaminess, while the fresh herbs like parsley sprinkled on top not only add color but also a fresh flavor that brightens the dish. This casserole can also serve as a fantastic filling for wraps or alongside grains like quinoa or brown rice for a wholesome meal.

Ingredients

Vegetables

2 cups zucchini, sliced
2 cups bell peppers, diced
1 cup carrots, diced
1 cup broccoli florets
1 cup mushrooms, sliced

For the Béchamel Sauce

4 tablespoons butter
4 tablespoons all-purpose flour
2 cups milk
1 cup cheddar cheese, grated
1/2 cup parmesan cheese, grated
Salt and pepper to taste

Toppings

1 cup breadcrumbs
1 tablespoon olive oil
1 tablespoon fresh parsley, chopped

Instructions

Preheat the Oven

Preheat your oven to 375°F (190°C) and grease a 9x13 inch baking dish.

Prepare the Vegetables

In a large skillet, heat a splash of olive oil over medium heat. Add the sliced zucchini, diced bell peppers, carrots, broccoli, and mushrooms. Sauté for about 5 minutes until just tender.

Make the Béchamel Sauce

In a saucepan, melt the butter over medium heat. Stir in the flour to create a roux and cook for 2 minutes. Gradually whisk in the milk, stirring continuously until the sauce thickens. Add the cheddar cheese and season with salt and pepper.

Assemble the Casserole

Layer the sautéed vegetables in the greased baking dish. Pour the béchamel sauce over the vegetables, ensuring an even coat. Mix the breadcrumbs with olive oil and parsley, then sprinkle over the top.

Bake

Bake in the preheated oven for 30-35 minutes, or until the topping is golden brown and the casserole is bubbling.

Serve

Allow the casserole to cool for a few minutes before slicing. Serve warm and enjoy!

Pro Tips

For an added boost of flavor, try incorporating roasted garlic into the béchamel sauce. You can also use different types of cheese like gouda or feta for a unique twist.

Common Troubleshooting Tips

If you find your casserole is too watery, it’s likely due to the vegetables releasing excess moisture while baking. To combat this, consider salting your vegetables before sautéing to draw out some moisture. Also, be sure to thoroughly sauté your vegetables beforehand and avoid overcrowding the pan, which could trap steam and lead to a soggy casserole.

Alternatively, if the top isn’t browning as expected, you can place it under the broiler for the last few minutes, but keep a close watch to prevent burning. This not only achieves a beautiful golden topping but also adds a delightful crunch that contrasts with the creamy base.

Dietary Adaptations

For those following a vegan diet, swapping out butter for vegan margarine and using a plant-based milk, along with nutritional yeast for a cheese-like flavor can adapt this casserole beautifully. You can also find vegan cheese options that melt well and can be incorporated into the béchamel sauce, retaining the dish's creamy consistency.

Gluten-free options can easily be achieved by using gluten-free all-purpose flour for the béchamel. Ensure your breadcrumbs are also gluten-free if you plan to use them for the topping. This way, everyone can enjoy this comforting dish without dietary restrictions holding them back.

Scaling the Recipe

This recipe is highly scalable, perfect for feeding a crowd or for meal prepping. To double the recipe, simply use a larger baking dish, and ensure you have ample oven space. Keep in mind that baking times might vary slightly with larger quantities; check for doneness by ensuring the internal temperature reaches 165°F (74°C).

If you want to make smaller portions, consider using individual ramekins. This not only looks appealing when serving but also reduces baking time. Experiment with different vegetable combinations to keep things interesting and cater to different tastes and preferences of your guests.

Questions About Recipes

→ Can I prepare the casserole in advance?

Yes! You can assemble the casserole a day ahead and store it in the fridge. Just bake it when you're ready to serve.

→ What vegetables can I use?

Feel free to use any vegetables you have on hand, such as spinach, cauliflower, or eggplant.

→ Can I freeze leftovers?

Absolutely! Just make sure to cool the casserole completely before wrapping it tightly and storing it in the freezer.

→ How do I reheat the casserole?

You can reheat it in the oven at 350°F (175°C) for about 20 minutes, or until heated through.