Veggie Roasted Vegetables Casserole

Finding a reliable side dish that works for busy weeknights and special dinners alike can feel nearly impossible. You want something that tastes great, doesn’t require constant attention in the kitchen, and actually uses up those vegetables sitting in your fridge before they go bad.

That’s where this roasted vegetables casserole comes in handy. It’s hearty enough to satisfy everyone at the table, easy to throw together on a weeknight, and flexible enough that you can swap in whatever vegetables you need to use up.

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What Kind of Roasted Vegetables Should I Use?

The beauty of this casserole is that you can really use whatever vegetables you have on hand or prefer. Heartier vegetables like carrots, broccoli, cauliflower, and sweet potatoes work great because they hold up well to roasting and baking without getting mushy. If you want to add softer vegetables like asparagus or zucchini, just keep in mind they’ll have a more tender texture in the final dish. You can also mix and match based on what’s in season or what’s on sale at the grocery store – bell peppers, Brussels sprouts, and butternut squash are all solid choices. Just make sure to cut everything into similar-sized pieces so they roast evenly.

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Options for Substitutions

This casserole is really forgiving when it comes to swapping ingredients:

• Roasted vegetables: Feel free to use whatever vegetables you have on hand or prefer. Zucchini, bell peppers, cauliflower, Brussels sprouts, or butternut squash all work great. Just make sure to roast them until they’re tender before adding to the casserole.
• Cheddar cheese: Any melty cheese works here. Try Gruyere for something fancy, mozzarella for a milder taste, or pepper jack if you want a little kick.
• White roux: If you don’t want to make a roux from scratch, you can use 1 can of cream of mushroom or cream of chicken soup thinned with 1/2 cup of milk.
• Ritz crackers: Panko breadcrumbs, crushed cornflakes, or even crushed potato chips make a good crunchy topping. Just toss them with the melted butter the same way.
• Butter: Olive oil or melted coconut oil can replace the butter if needed, though butter does give the best flavor for the topping.

Watch Out for These Mistakes While Baking

The biggest mistake when making roasted vegetable casserole is adding vegetables that are undercooked or still have too much moisture, which can make your casserole watery and prevent it from setting properly – make sure your vegetables are fully roasted and let them cool slightly before mixing them in.

Another common error is not seasoning each layer separately, so taste your roux and season your vegetables before combining them, since it’s nearly impossible to fix bland flavors once everything is baked together.

To avoid a soggy topping, wait until the last 15 minutes of baking to add your buttered Ritz cracker crust, which keeps it crispy instead of letting it sink into the casserole and turn mushy.

If your casserole looks too thick, don’t be afraid to thin out the roux with a bit of milk or vegetable broth before assembling, as the mixture will continue to thicken as it bakes.

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What to Serve With Roasted Vegetable Casserole?

This casserole is pretty hearty on its own, but it pairs beautifully with simple proteins like roasted chicken, grilled pork chops, or even a juicy steak. If you’re keeping things vegetarian, serve it alongside a fresh arugula salad with lemon vinaigrette to balance out the richness of the cheese and roux. I also love making this casserole for holiday dinners where it sits perfectly next to ham or turkey, and the buttery Ritz cracker topping makes it feel special enough for any gathering. For a lighter meal, pair it with some crusty bread and a simple tomato salad.

Storage Instructions

Store: Keep your leftover casserole covered tightly with foil or in an airtight container in the fridge for up to 4 days. The flavors actually get even better the next day, making it a great option for meal prep or potluck leftovers.

Freeze: This casserole freezes really well for up to 3 months. You can freeze it either before or after baking – just wrap it tightly in plastic wrap and then foil. If freezing unbaked, add about 15 extra minutes to the baking time when you’re ready to cook it.

Reheat: Warm it up in the oven at 350°F covered with foil until heated through, about 20-25 minutes. You can also microwave individual portions for 2-3 minutes, though the cracker topping won’t be quite as crispy that way.

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

• Calories: 1700-2000
• Protein: 30-36 g
• Fat: 90-110 g
• Carbohydrates: 180-220 g

Ingredients

For the vegetable mixture:

• 2 cups roasted vegetables
• 1/2 cup cheddar cheese (I prefer sharp cheddar)
• 1 tbsp garlic (minced)
• 1 tsp salt
• 1 tsp black pepper (freshly ground preferred)
• 1/2 cup chopped onion
• 2 cups white roux

For the topping:

• 2 tbsp butter, melted (I use Kerrygold)
• 1 sleeve Ritz crackers (crushed)

Step 1: Prepare the Baking Dish and Layer Vegetables

• 2 cups roasted vegetables
• 1/2 cup chopped onion

Preheat the oven to 350°F (175°C) and lightly spray a 9 x 13 inch baking dish with cooking spray.

Evenly distribute the roasted vegetables and chopped onion in the prepared dish.

Step 2: Season and Mix the Casserole Base

• 1 tbsp garlic (minced)
• 1 tsp salt
• 1 tsp black pepper (freshly ground preferred)
• 1/2 cup cheddar cheese (I prefer sharp cheddar)
• 2 cups white roux

Sprinkle the minced garlic, salt, and freshly ground black pepper over the vegetables and onions.

Mix everything together thoroughly.

After seasoning, gently fold in the cheddar cheese and white roux until the mixture is well combined and evenly coated.

I like to use sharp cheddar for extra flavor.

Step 3: Add Cracker Topping

• 1 sleeve Ritz crackers (crushed)
• 2 tbsp butter, melted (I use Kerrygold)

Sprinkle the crushed Ritz crackers evenly over the top of the casserole.

Drizzle the melted butter over the cracker crumbs to help them crisp up during baking.

I use Kerrygold butter for its rich taste.

Step 4: Bake and Serve

Bake the casserole uncovered in the preheated oven for 30 minutes, until the top is golden and bubbling.

Remove from the oven and let rest for 5 minutes before serving, which helps everything set nicely.

Veggie Roasted Vegetables Casserole

Delicious Veggie Roasted Vegetables Casserole recipe with step-by-step instructions.

Print Recipe Pin Recipe

Prep Time 15 minutes mins

Cook Time 32 minutes mins

Total Time 47 minutes mins

Servings 4

Calories 1850 kcal

Ingredients

  

For the vegetable mixture:

• 2 cups roasted vegetables
• 1/2 cup cheddar cheese (I prefer sharp cheddar)
• 1 tbsp garlic (minced)
• 1 tsp salt
• 1 tsp black pepper (freshly ground preferred)
• 1/2 cup chopped onion
• 2 cups white roux

For the topping:

• 2 tbsp butter, melted (I use Kerrygold)
• 1 sleeve Ritz crackers (crushed)

Instructions

 

• Preheat the oven to 350°F (175°C) and lightly spray a 9 x 13 inch baking dish with cooking spray. Evenly distribute the roasted vegetables and chopped onion in the prepared dish.
• Sprinkle the minced garlic, salt, and freshly ground black pepper over the vegetables and onions. Mix everything together thoroughly. After seasoning, gently fold in the cheddar cheese and white roux until the mixture is well combined and evenly coated. I like to use sharp cheddar for extra flavor.
• Sprinkle the crushed Ritz crackers evenly over the top of the casserole. Drizzle the melted butter over the cracker crumbs to help them crisp up during baking. I use Kerrygold butter for its rich taste.
• Bake the casserole uncovered in the preheated oven for 30 minutes, until the top is golden and bubbling. Remove from the oven and let rest for 5 minutes before serving, which helps everything set nicely.