Veggie Casserole Recipe

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This cozy Veggie Casserole Recipe is a perfect addition to your Thanksgiving table! With California blend veggies, corn, and green beans in a creamy mushroom and sour cream mix, it’s topped with crispy fried onions and Parmesan. Baked until golden and bubbly, it’s an easy, crowd-pleasing side that brings warmth and flavor to your holiday feast.

White plate filled with a baked vegetable casserole.

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This Thanksgiving side dish is sure to shine, bringing a creamy, comforting bite to your Thanksgiving table. If you're looking for an extra cheesy option, check out our California blend casserole.

To round out your holiday side dish spread, pair this make-ahead veggie casserole with our green bean bundles for a double dose of vegetables - or add some richness with this loaded baked potato casserole for an irresistible, flavorful twist. Together, these recipes create a Thanksgiving feast that’s sure to be a hit!

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Why You'll Love This Veggie Casserole Recipe
How to Make Veggie Casserole in a Slow Cooker
Ingredients
Substitutions & Variations
Complete Your Thanksgiving Meal
How to Make the Best Veggie Casserole
Helpful Tips
Recipe FAQs
Storage & Freezing Instructions
More Thanksgiving Side Dishes You'll Love
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Veggie Casserole Recipe

Why You'll Love This Veggie Casserole Recipe

Convenient and easy to make - Canned veggies are super convenient to use and taste great in this casserole, making it take just 5 minutes to prep!
Meat free option for Thanksgiving - This casserole is great in addition to your Thanksgiving turkey (or turkey breast) or other main dishes, offering a meat-free option made with delicious veggies!
Make-ahead and travel-friendly - This casserole can easily be made up to 2 days in advance and simply popped in the oven when you’re ready to serve. This makes it great for traveling and saves you time on the busy day-of!
Versatile and simple to customize - There is an endless variety of vegetables and seasonings you can use with this casserole, making it a great customizable dish to fit your preferences!

How to Make Veggie Casserole in a Slow Cooker

Combine all of the ingredients (except the crispy topping) and cook on low for 4-5 hours or high for 2-3 hours. To crisp the topping, add it 15-30 minutes before serving and, if you have an oven-safe slow cooker insert, place it under the broiler for 1-2 minutes before returning it to the slow cooker to keep warm.

Ingredients

Gather the ingredients below to make this easy veggie casserole!

California blend vegetables are a mix of broccoli, cauliflower, and carrots and they are the heart of this veggie casserole.
Sweet corn adds a light sweetness and is a classic casserole ingredient.
Beans make this casserole hearty and nutritious!
Cream of mushroom soup is rich, creamy, and full of great flavor. It holds the vegetables together and makes the casserole taste cohesive.
Sour cream brings even more creaminess to the casserole and a bit of tangy flavor!
Garlic powder enhances the flavor of the veggie casserole and brings the classic garlic flavor that we all know and love!
Crispy fried onions are the perfect topping for this casserole, bringing a satisfying crunch and a savory, salty flavor.
Shredded parmesan cheese adds a sharp, tangy flavor that brings this veggie casserole to the next level.

See recipe card for full information on ingredients and quantities.

Substitutions & Variations

In place of crispy fried onions, you can use Ritz crackers or breadcrumbs to top your casserole.
You can use a variety of cheeses in addition to or instead of parmesan. Monterey jack, cheddar, and pepper jack are just a few great options.
There’s an endless variety of vegetables that you can use in this casserole. Bell peppers, green beans, peas, mushrooms, and zucchini are some examples, but feel free to add your favorite veggies and customize this dish to your liking.
You can use fresh vegetables as opposed to canned or frozen veggies if preferred. You will need around 4 cups of vegetables in total.

Complete Your Thanksgiving Meal

For a memorable Thanksgiving feast aside from the turkey, pair this veggie casserole with my loaded cheese ball as a delicious appetizer, cranberry fluff salad for a tangy side, and praline pumpkin pie as a sweet finish. These festive flavors will make your holiday table complete!

How to Make the Best Veggie Casserole

Once you've gathered all your ingredients, preheat the oven to 350ºF and follow the steps below to make this comforting veggie casserole recipe.

A mixing bowl filled with vegetables, cream of mushroom soup, sour cream, crispy onions and seasonings.

Step 1: In a large mixing bowl, combine all vegetables, cream of mushroom, sour cream, seasonings, and 4 oz of crispy fried onions. Stir well.

Baking pan filled with mixed vegetables covered in a creamy sauce.

Step 2: Transfer mixture to a greased 9x13-inch baking dish.

Veggie casserole sprinkled with with crispy fried onions.

Step 3: Evenly sprinkle cheese over top followed by remaining crispy fried onions.

Pan of cooked vegetables topped with crispy fried onions.

Step 4: Bake for 40 minutes or until mixture is bubbling and onions are golden brown.

Serving spoon digging into a baking dish filled with a vegetable casserole.

Helpful Tips

Draining excess liquid from veggies is important to prevent mushiness.
If you are reheating leftovers, add more crispy onions before reheating.
For a little added depth, try mixing a dash of smoked paprika or a sprinkle of Italian seasoning into the casserole before baking. A few fresh herbs like parsley or thyme on top also add a nice finish.
If you want an extra-crispy topping, broil the casserole for 1-2 minutes at the end of baking. Just keep a close eye on it to avoid burning!
This casserole can be assembled a day ahead and stored in the fridge (without the crispy topping) until you’re ready to bake. Add the topping just before baking for best results.
When reheating leftovers, add a few tablespoons of milk or cream to keep the casserole from drying out. Then cover and bake as directed.

A heaping plate filled with colorful veggie casserole.

Recipe FAQs

Can I use fresh vegetables instead of frozen and canned?

Absolutely! Fresh vegetables work well in this veggie casserole recipe, though it may help to blanch them briefly to soften slightly before baking. Use about 4 cups of chopped vegetables in total for the best balance.

What other cheeses could I use in this California blend vegetable casserole?

While Parmesan adds great flavor, other cheeses like cheddar, Monterey Jack, or pepper jack work well too. For a sharper taste, try aged cheddar, or go for a creamier texture with mozzarella. You can use a single type of cheese or a mix.

Can I make this Thanksgiving casserole ahead of time?

Yes! You can prepare the casserole up to 1-2 days in advance. Assemble it without the crispy topping and store it covered in the refrigerator. When ready to bake, add the topping, then bake as directed. This saves time on the day you plan to serve it!

Plate filled with a veggie casserole topped with French fried onions.

Storage & Freezing Instructions

Storage Instructions

To store the casserole, place it in an airtight container in the refrigerator for up to 3 days.

Freezing Instructions

To freeze this dish, tightly wrap the casserole in a freezer safe container and leave it in the freezer for up to 3 months. To reheat, let the casserole thaw in the refrigerator overnight and then cook at 350ºF until warmed through.