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 of diced bell peppers (red, yellow, and green); 2 cups of chopped zucchini; 2 cups of fresh spinach; 1 cup of chopped onions; 1 cup of cherry tomatoes, halved; 2 tablespoons of olive oil; 2 tablespoons of all-purpose flour; 2 cups of milk; 1 teaspoon of salt; 1/2 teaspoon of black pepper; 1/4 teaspoon of nutmeg; 1 cup of shredded mozzarella cheese; 1/2 cup of grated Parmesan cheese; 1 cup of breadcrumbs

Highlighted under: Pastry Magic

I love how Sunday Baked Vegetable Casserole brings together a medley of flavors that make my family gather around the table with smiles. Each bite is a comforting embrace of roasted vegetables, creamy sauce, and a bubbly cheese topping. I've found that roasting the vegetables beforehand enhances their natural sweetness, which really elevates the dish. Whether you serve it as a main or a side, it's hearty enough to satisfy everyone. Trust me, this casserole is a delightful way to enjoy your veggies!

Created by

Elara Whitfield

Last updated on 2026-01-13T23:16:10.328Z

One Sunday afternoon, I decided to experiment with a vegetable casserole that would satisfy my family’s diverse tastes. I roasted bell peppers, zucchini, and spinach, and added a creamy béchamel sauce mixed with a hint of nutmeg. The smell filled the kitchen and when it came out of the oven, the bubbling cheese had melted beautifully, forming a golden crust on top. It was simply irresistible!

As we sat down to enjoy the dish together, I realized that cooking is about sharing experiences. Our conversations flowed easily, and everyone raved about how the flavors blended so well. I’ve discovered that adding a sprinkle of fresh herbs just before serving elevates it even further and adds brightness to the dish.

        Why You'll Love This Recipe
        A colorful array of roasted vegetables packed with flavor
Creamy texture combined with a satisfying crunchy topping
Perfect for meal prep and can be easily customized with seasonal veggies

      

Understanding the Flavor Profiles

The combination of the roasted vegetables creates a rich flavor profile that is both sweet and savory. Roasting the bell peppers, zucchini, and onions enhances their natural sugars, which caramelize beautifully during the cooking process. For a variation, consider adding vegetables like eggplant or asparagus, which also hold up well to roasting and bring unique flavors. The burst of sweetness from the cherry tomatoes adds an interesting contrast to the creaminess of the sauce.

The béchamel sauce is the heart of this casserole, providing a creamy base that binds the flavors together. Incorporating nutmeg adds a subtle warmth and depth, enhancing the overall experience. For a lactose-free option, try using almond or oat milk with a thickener like cornstarch instead of flour. This will maintain a similar texture and consistency while accommodating dietary preferences.

Tips for Perfect Layering

When layering the casserole, ensure the roasted vegetables are evenly distributed to create a uniform flavor in every bite. I recommend placing the vegetables in a single layer on the bottom before pouring the béchamel sauce on top. This helps ensure that the sauce seeps into the vegetables, allowing the flavors to meld beautifully. Using a spatula to gently stir the mixture before adding cheese can help distribute the sauce without disrupting the layers too much.

If you prefer a crispier topping, consider broiling the casserole for a couple of extra minutes after baking. Keep a close eye, as it can go from perfectly golden to burnt quickly. Also, you can add herbs or spices to the breadcrumb topping before baking, like garlic powder or dried herbs, for an extra flavor boost that complements the vegetables.

Ingredients

Gather these fresh ingredients for a delightful casserole.

Vegetables

2 cups of diced bell peppers (red, yellow, and green)
2 cups of chopped zucchini
2 cups of fresh spinach
1 cup of chopped onions
1 cup of cherry tomatoes, halved

Sauce

2 tablespoons of olive oil
2 tablespoons of all-purpose flour
2 cups of milk
1 teaspoon of salt
1/2 teaspoon of black pepper
1/4 teaspoon of nutmeg

Topping

1 cup of shredded mozzarella cheese
1/2 cup of grated Parmesan cheese
1 cup of breadcrumbs

Mix and match your favorite vegetables to create this hearty dish!

Instructions

Follow these steps to bake a delicious casserole.

Preheat the Oven

Preheat your oven to 375°F (190°C).

Roast the Vegetables

In a large bowl, mix all the diced vegetables with olive oil, salt, and pepper. Spread them on a baking tray and roast for about 25 minutes until tender and slightly caramelized.

Prepare the Sauce

In a saucepan over medium heat, whisk together flour and olive oil to create a roux. Gradually add milk, stirring constantly until the sauce thickens. Add nutmeg, salt, and pepper.

Combine and Layer

In a large baking dish, layer the roasted vegetables, then pour the béchamel sauce over them. Top with mozzarella, Parmesan, and breadcrumbs.

Bake

Bake in the preheated oven for 20 minutes, or until the top is golden and bubbling.

Serve and Enjoy

Remove from oven and let it cool for a few minutes. Serve warm and enjoy the delightful flavors.

Don’t forget to garnish with fresh herbs before serving!

Pro Tips

For a gluten-free option, use gluten-free flour for the béchamel sauce. This dish also freezes well, so consider making a double batch for future meals.

Make-Ahead and Storage Tips

This casserole is fantastic for meal prep; you can assemble it the night before and refrigerate it. Just cover it tightly with plastic wrap or foil. If you're prepping for a gathering, you can freeze a fully assembled dish before baking. When ready to cook, simply thaw it in the refrigerator overnight and then bake as instructed. Freezing can help develop the flavors even further, making it a comforting option for busy nights.

Leftovers store exceptionally well. Store any uneaten casserole in an airtight container in the fridge for up to four days. While reheating, add a splash of milk or a little water to help keep the texture creamy. Reheat in the oven for 15-20 minutes at 350°F (175°C) to bring back the bubbly top and warmth, or use the microwave for a quick fix, stirring halfway through for even heating.

Serving Suggestions

This casserole works beautifully as a main dish when accompanied by a light side salad drizzled with vinaigrette. The freshness of the salad balances the richness of the casserole. Alternatively, you can serve it as a side with grilled meats or roasted chicken for a complete meal that satisfies all kinds of eaters at the table.

For a bit of added texture and flavor, consider drizzling a balsamic reduction over the casserole just before serving. This tangy addition complements the sweetness of the dish and elevates the presentation. You can also experiment by adding fresh herbs like basil or parsley on top just before serving, which provides a refreshing finish.

Questions About Recipes

→ Can I use frozen vegetables?

Yes, frozen vegetables can be used but ensure they are fully thawed and drained before roasting.

→ What can I substitute for milk?

You can substitute dairy milk with almond milk or any plant-based milk.

→ How long does leftovers last?

Leftovers can be stored in the refrigerator for up to 3 days.

→ Can I make this casserole ahead of time?

Absolutely! You can prepare everything a day ahead, just bake it before serving.