Creamy, cheesy, and full of flavor, this easy vegetable casserole recipe uses thawed frozen vegetables for the simplest hearty side. Just five ingredients and five minutes of prep yields a dish that tastes like it simmered for hours.
Because it starts with frozen vegetables, this casserole is a true shortcut: as it bakes the ingredients meld into a rich, comforting flavor. A final sprinkle of salty French fried onions provides a crunchy contrast that keeps guests coming back for more.
Swap this casserole in for traditional green bean casseroles at holiday dinners or make it any night as a satisfying, flavorful side. It’s a great complement to dishes like roasted turkey, mashed sweet potatoes, or a simple roast chicken.
Table of Contents
- Why you will find this dish comforting:
- Professional Tips for Making Broccoli Cheese Casserole:
- Ingredients
- Variations
- How to Make this Vegetable Casserole:
- Chef Lindsey’s Recipe Tip
- Frequently Asked Questions
- Vegetable Casserole Recipe
- Before You Go!
Why you will find this dish comforting:
- Only 5 ingredients and 5 minutes to prep. This is genuinely a quick, low-effort casserole that still delivers big flavor.
- Scales easily. Mix and bake a larger batch in one dish or divide between pans. Increase portions using the recipe card controls below.
- Versatile side. It pairs well with holiday mains, weeknight roasts, or a simple salad—creamy, cheesy, and satisfying alongside many entrees.
Professional Tips for Making Broccoli Cheese Casserole:
- Thaw frozen vegetables overnight in the refrigerator for best texture. If short on time, defrost in the microwave at 50% power.
- Drain excess liquid. Frozen vegetables release moisture as they thaw; drain well so the casserole isn’t watery.
- If you expect leftovers, only top the portion you’ll serve immediately with fried onions. Add the remaining onions when reheating to preserve crunch.
Ingredients
- Mixed frozen vegetables: A broccoli, carrot, and cauliflower blend works well. Thaw and drain before combining.
- Condensed cream of mushroom soup: Use your preferred brand; it forms the creamy base of the casserole.
- Shredded Swiss cheese: Use a good melting Swiss (or Emmental) and reserve half for topping.
- Sour cream: Adds tang and extra creaminess; full-fat or light will both work.
- Kosher salt and black pepper: Season to taste, keeping in mind canned soup can add saltiness.
- French fried onions: Add just before serving for a salty, crispy finish. Alternatively, use crushed butter crackers for crunch.
See the recipe card below for exact quantities and complete instructions.
Variations
- Ritz crackers: Swap fried onions for crushed Ritz or butter crackers for a crunchy topping without onion flavor.
- Cheese options: Try mozzarella, Gruyère, fontina, or sharp cheddar for a different flavor profile.
- Add corn: Stir in frozen corn for extra sweetness and texture.
How to Make this Vegetable Casserole:
Follow these straightforward steps for a reliably delicious casserole. Full measurements are in the recipe card below.
Step 1: Preheat oven to 350°F.
Step 2: In a bowl, combine thawed, drained vegetables with the condensed soup, ½ cup shredded Swiss, sour cream, and black pepper. Stir until evenly coated and transfer to a 1-quart casserole dish.
Taste before baking and add kosher salt if the soup isn’t very salty. Adjust seasoning to your preference.
Step 3: Cover and bake for 30 minutes.
Step 4: Remove cover, sprinkle with remaining cheese and French fried onions, and bake uncovered for 5 more minutes until cheese is melted and topping is warmed. Taste and adjust seasoning if needed, then serve hot.
For an attractive presentation, bring the casserole to the table so guests can serve themselves from the hot, bubbly dish.
Chef Lindsey’s Recipe Tip
Frozen vegetables are a convenient, nutritious choice. They’re typically flash-frozen at peak freshness, preserving vitamins and flavor while saving you prep time.
Frequently Asked Questions
Store leftovers in an airtight container in the refrigerator for up to 7 days. Add fried onions just before serving to keep them crisp. You can freeze the baked casserole for up to 6 months in a freezer-safe container.
From refrigerated: Place in a covered oven-safe dish and rewarm at 350°F until heated through, then add crispy onions. From frozen: Thaw overnight in the fridge and reheat as above, or bake covered from frozen for a longer time until bubbly.
No—frozen, defrosted vegetables have been blanched and will finish cooking in the oven while the casserole bakes.
Yes. Assemble the casserole up to three days ahead, keep it covered in the refrigerator, and bake when ready. You can also bake it ahead and rewarm before serving.
If you try this recipe and enjoy it, please leave a star rating and a comment below—feedback is always appreciated.
Vegetable Casserole
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Ingredients
- 16 oz frozen broccoli, carrots and cauliflower mix — thawed and drained
- 12 oz condensed cream of mushroom soup (one 10–12 oz can)
- 1 cup shredded Swiss cheese, divided (about 4 oz)
- ⅓ cup sour cream
- ¼ teaspoon ground black pepper
- kosher salt to taste
- 2.8 oz French fried onions
Instructions
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Preheat oven to 350°F.
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Combine thawed vegetables, condensed soup, ½ cup shredded Swiss, sour cream, and pepper. Mix and pour into a 1-quart casserole dish.
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Bake covered for 30 minutes.
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Sprinkle remaining cheese and French fried onions on top and bake uncovered 5 minutes more. Taste and add salt if needed. Serve hot.
Video
Notes
Variations – Use crushed crackers instead of fried onions or try different melting cheeses.
Storage – Refrigerate leftovers in an airtight container up to 7 days. Add fried onions when serving. Freeze up to 6 months.
This simple, classic recipe takes about 5 minutes to prepare and serves 8.
Nutrition
Before You Go!
I hope you enjoyed this chef-tested recipe. Try more easy, chef-developed side dishes for your next meal.
