Creamy, cheesy, flavorful. 5 ingredients and 5 minute prep time. This Easy Swiss Cheese Mixed Vegetable Casserole couldn’t be easier yet it has a surprisingly dynamic flavor! This is the least fussy side dish that will get rave reviews!
This Creamy Swiss Cheese Mixed Vegetable Casserole is made with thawed frozen vegetables for the ultimate prep shortcut. As it bakes, the flavors meld and it tastes like it took hours! There is even a little salty crunch from the fried onions to make this dish a smash hit that will have folks fighting over seconds!
Try this casserole instead of the usual green bean casserole at your next holiday feast or just whip this up any day of the week for a hearty, flavorful side dish! You just won’t believe how easy it is. The instructions say 5 minutes of prep and that is literally all it takes including cleanup. This means more time for Sweet Potato Casserole and scalloped potatoes! Or, if you are me, that means time to make just one more pie! 😂
Table of Contents
Ingredients for Creamy Swiss Cheese Mixed Vegetable Casserole
- Mixed Frozen Vegetables: I use those mixed bags of frozen broccoli, carrots and cauliflower, but you could certainly add other varieties. Every brand has a different size bag, so be sure to get enough.
- Sour Cream: I use full fat sour cream but low fat could also be used. Sour cream adds the extra creaminess in this Swiss cheese mixed vegetable casserole with a little amplified tang.
- Condensed Cream of Mushroom Soup: I use organic Pacific brand Condensed Cream of Mushroom Soup because I prefer the flavor and it has lower sodium than other brands, but you can use any brand you choose.
- Swiss Cheese: Swiss Cheese comes in a wide variety of qualities and flavors just like all other cheese. You can certainly use pre-shredded Swiss Cheese but I love to go the extra mile and shred my own. I specifically look for Emmental cheese, which is a Swiss cheese from the Emmental region in Switzerland. It generally has a richer, more robust flavor.
- Kosher Salt: Depending on the brand of soup you choose, you might need to add a little extra kosher salt to taste.
- French Fried Onions: French Fried Onions are unquestionably a magical thing. Salty, crispy fried onions in a can! Add right before serving or they will get soggy.
How to make an Easy Mixed Vegetable Casserole?
Time needed: 35 minutes.
How to make Easy Mixed Vegetable Casserole?
- Pre-heat the oven.
Preheat your oven to 350°F.
- Mix Casserole.
Combine thawed frozen vegetables, condensed cream of mushroom soup, ½ cup Swiss cheese, sour cream, and black pepper in a bowl. Taste and add kosher salt if needed. Pour into a 1-quart, oven-safe casserole dish.
- Bake Casserole.
Cover with foil and bake for 30 minutes. After 30 minutes remove covering and sprinkle the top with remaining cheese. Continue baking uncovered, 5 minutes longer.
- Serve Casserole.
Top with French Fried Onions and serve!
Frequently Asked Questions
Store this easy Swiss Cheese Mixed Vegetable Casserole covered in the refrigerator for up to 7 days. You can also transfer it to a freezer-safe container and freeze it. I do not add the French Fried Onions until ready to serve because they get soggy in the refrigerator.
This easy casserole will keep for up to a week refrigerated or up to 2 months frozen.
You can freeze Swiss Cheese Mixed Vegetable Casserole. It freezes very well. Transfer to a freezer-safe storage container or zip-top baggie.
From Refrigerated: Reheat, covered, in a preheated 350°F oven. I usually store it in the original baking dish, which makes this easy, but you could also transfer it to another oven-safe dish before reheating. Bake until hot and bubbly. Top with crispy onions and serve.
From Frozen: Allow to thaw in the refrigerator overnight and follow instructions above, or cover and bake from frozen in an oven-safe dish. It will take longer but will be equally delicious.
You can make this Swiss Cheese Mixed Vegetable Casserole up to 3 days ahead. I prefer to mix the filling and then cover and refrigerate unbaked, but it can also be baked ahead and rewarmed according the instructions above.
It is easiest to place the bag of frozen vegetables in the refrigerator the night before to thaw, but I have also thawed them in the microwave at 50% power in a pinch.
What to serve with Creamy Swiss Cheese Mixed Vegetable Casserole?
I made this Easy Swiss Cheese Mixed Vegetable Casserole as part of my Thanksgiving Menu 2022, but you could also serve it alongside maple mashed sweet potatoes and my Easy Dinner Rolls! The creaminess of the dish would also pair beautifully with a simple side salad. Serve it with a roasted chicken or my foolproof rosemary chicken for an easy weeknight meal!
Chef Lindsey's Recipe Tips
If you forget to thaw your veggies in advance, not to worry! I just microwave them at 50% power to defrost and everything works out.
Recipe
Creamy Swiss Cheese Mixed Vegetable Casserole
Ingredients
- 16 oz frozen broccoli, carrots and cauliflower mix (thawed and drained)
- 12 oz condensed cream of mushroom soup canned (I use organic Pacific brand but you can use a standard 10 oz can too)
- 1 cup shredded Swiss cheese, divided (4 oz )
- ⅓ cup sour cream
- ¼ teaspoon Ground Black Pepper
- 2.8 oz French Fried Onions
Instructions
- Preheat your oven to 350°F.
- I forgot to thaw my vegetables so I just microwaved them until they were thawed. Some were warm, but it didn’t make one bit of difference.
- Combine vegetables, soup, ½ cup cheese, sour cream, and pepper. Pour into a 1-quart casserole.
- Bake for 30 minutes. The original instructions say to bake it covered but I forgot.
- Top with remaining cheese and onions; bake uncovered, 5 minutes longer.
Video Instructions
Notes
Before You Go!
Check out our other delicious, chef-developed recipes for Side Dishes!
Oh so cheesy!! I love recipes which involves cheeseeee.. this casserole looks insanely delicious. . Can't wait to try this.. Love it!! 🙂
This sounds so easy, and looks so cheesy and delicious! Who says green beans get to have all the fun -- love this variety of veggies!
Sounds and looks delicious. A great choice for a quick dinner. Love it.
Thanks, Ella!
All this creaminess is simply fantastic! 😀 I'll surely try it!
Thanks, Michela!
Oh god this looks so cheesy and delicious. Wish I had a bowl of it tonight for dinner!
Me too! Thank you!
Wonderful side dish Lindsay! Looks like easy to make too 🙂
Thanks, Valya! It definitely is!
so cheesy. so dreamy 🙂 haha
This casserole looks amazing, Lindsey! What a fun and delicious way to serve up frozen vegetables and especially with those crispy fried onions! Love how quick and easy this is to whip up too!
Thanks, Kelly!! So easy! There needs to be at least one easy dish for Thanksgiving!
This looks hearty and delicious! The perfect winter comfort meal! Pinning! Have a nice Thanksgiving!
Thanks, Mira! It is definitely great for those cold, winter days! Happy Thanksgiving to you too!
love how cheesey and creamy this looks! Happy Thanksgiving Lindsey!
Thanks, Manali! Happy Thanksgiving to you too!
This casserole looks amazing, love the cheesy flavour with the veggies! Perfect mid-week meal!
Thanks, Jess!
Lady - your photos are awesome! I am not a huge fan of condensed soups - but even I would try this casserole - your pictures make it phenomenal!
BTW, Happy Thanksgiving Lindsey!
Thanks, Shashi! I only use them occasionally. I'll admit that my first bite was a "no-thank you bite" but then I couldn't stop!! I also use an organic condensed mushroom soup with ingredients that I recognize and it comes in a box not a can! hoity-toity. Happy thanksgiving to you too!
Quick and easy...now that's how I roll during the holidays! And this casserole looks like the ultimate comfort food. You've got cheesy. You've got creamy. You've got crunchy. You even threw in some veggies. Nicely done, Lindsey! Happy (early) Thanksgiving!
Haha! Thanks, David! I'm not gunna lie, those onions were my favorite part. My newest guilty pleasure!
I'm loving all of the cheesy goodness in this casserole, Lindsey! Swiss cheese is my favorite, yet a lot of people don't cook with it! This casserole is such a fun way to jazz up some vegetables. Pinned!
That's so true, Gayle! I don't see it much except on sandwiches. This is such a delicious use of it! Thanks for the pin!
Simple and delicious! Love it! And those crispy salty onions on top - forget about it!
Thanks, Annie! They are the best part for sure!
Wow, what a comforting casserole that looks like! I imagine it would be a hit at Thanksgiving 🙂
Thanks, Baby June! It such a quick and easy side dish especially for Thanksgiving!