Cheesy Onion Casserole: Best Thanksgiving Side Dish Ever!

Picture of Cheesy Onion Casserole: Best Thanksgiving Side Dish Ever!
No Thanksgiving is complete without a casserole and this one is literally as easy to make as it is to eat. With only a few ingredients and 30 minutes cooking time, it can easily be made between all the other more complicated Thanksgiving dishes.

Thanksgiving is a day of total hedonism where we gorge ourselves silly and have enough left overs for an army! Cheesy Onion Casserole, a family favorite, is so delicious the left overs are always fought over and we have to evenly and judiciously distribute or else the army is at war.

-Forkable Blog
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Step 1: Ingredients

Picture of Ingredients
2-3 Tbs butter or margarine
3 large sweet onions or 4 medium white or yellow onions
2 c. shredded Swiss cheese (8 oz.)
1 can cream of chicken soup, undiluted**
2/3 c. milk
1 tsp. soy sauce
8 or so slices of French bread

**You can substitute cream of mushroom soup for cream of chicken to make vegetarian.

Step 2: Slice onions

Picture of Slice onions
Slice onions and try not to cry. With this many onions, its hard.

Melt butter in a saute pan over medium heat, and add onions. Saute onions until clear, a little brown is ok. In a shallow 2 qt. casserole pan, layer onions, 2/3 of cheese and pepper to taste.

Step 3: Assemble Casserole

Picture of Assemble Casserole
Melt butter in a saute pan over medium heat, and add onions. Saute onions until clear, a little brown is ok. In a shallow 2 qt. casserole pan, layer onions, 2/3 of cheese and pepper to taste.

In a sauce pan, heat soup, milk, and soy sauce, stirring to blend. Pour soup mixture in a casserole and stir gently to mix. Top with bread slices. Bake at 350 uncovered for 15 minutes. After 15 minutes, top of bread should be nice and toasted.

Push bread slices under the sauce and top with the remaining cheese.

Step 4: Finish Baking and Eat!

Picture of Finish Baking and Eat!
Place casserole back in oven and finish baking for 15 more minutes.

Total prep time: 20 minutes.
Total baking time: 30 minutes.

Quick, simple and delicious!
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batonas7 months ago

I want to make this delicious mess, but where I live theres no cans of soup like that, maybe some real peaces of chicken would do the trick?

newsound8 months ago

This has become one of the most popular dishes for our gatherings. I've needed to start making two to keep everyone happy!

Bujholm11 months ago
Looks great! Like French onion soup but easier to make - at least in my case, when trying to make onion soup I ended up qith a munch of boiled onions. Here, it's not possible :)

I wonder though what would be a good substitute for the cream of mushrooms soup, for those of us who live in parts of the world where the Campbell's is not sold in stores :)
Real cream and canned mushrooms, with a bit of salt?
tavoarcila11 months ago
Thanks for the recipe, I'll try... to not to cry slicing the onions just wear swimming goggles, You'll look funny for a while but definitely won't cry :-p
tnbn11 months ago
Anyone try adding beef consumme and making this "French Onion" casserole??? Would it lack something without the creaminess of the soup?
lolson111 months ago
Fantastic...I even like this better (if possible) to have it on a day other than T-day! This is outstanding when served with roasted pork or standing rib roast...not as many competing flavors.
mdeblasi111 months ago
Because I am always looking for ways to avoid processed food. . .
What if, instead of cream of anything soup, you used heavy cream or evaporated milk (yes, I know)?
You may need to add an extra shot of soy sauce, in this case, or some nutritional yeast, to do some of the umami work the soup mix was doing.

Some people, when making french onion soup, add a a table spoon or two of flour to the sauteing onions, to act as a thickener, that might solve the problem of the wateriness, so that the emulsifiers in the soup are not necessary.
bryan314111 months ago
Ah, bringing pies to TG, but thank you for the recipe I'm using for my kayak club's Xmas potluck!
destructopop11 months ago
That just looks outrageously delicious!
I made this tonight and it was fabulous, I used Texas Toast in place of the french bread-we loved it!!
wolterwife1 year ago
Making this right now so far looks HEAVENLY! 5 more mins and it is ready to eat. I used less milk due to the fact I was afraid it would get too runny.
This was fantastic! I changed it a bit. Instead of the milk and soy sauce, I used cooking sherry with the same quantities. Was without a doubt a huge hit! I am making this over and over. It is a meal in itself...
StiltGuyJoe2 years ago
Made it, everyone loved it. Thanks for the recipe. :)
roxolsen3 years ago
I highly recommend preparing and cooking this outdoors. I will use my electric frying pan next time. The whole house smelled of onions for hours!
NotDaMomma3 years ago
lookin 4 easy recipes & ran across this. just had 2 make small sample. friend said he didn't know onions tasted so good now got 2 make it 4 family Thanksgiving.
HOLY CRAP that looks good!
I made this for thanksgiving. My family thought it was the weirdest thing. Half wouldn't try it, most didn't like it. Me, my daughter, and an aunt absolutely loved it... I'm actually craving some right now... =o/

The cheesy garlic butter biscuits from are perfect with it.
Aronbao4 years ago
it looks delicious
crapulence4 years ago
Hi Forkable! I made this for Thanksgiving and everyone loved it!  Very delicious! It did come out a little soupy, but next time I would use a condensed cream of mushroom/chicken soup (i used a non condensed cream of mushroom soup), I think that would thicken it up a bit.  Thanks again for an awesome recipe....a definite keeper! :o)  
 I did make this for Thanksgiving and it was a big hit! Too big a hit -- no leftovers for me! It tasted great though I thought it was a little soupy -- like I had added too much milk or didn't bake it long enough or maybe didn't cut the bread slices thick enough? I'll make this again for Christmas dinner. Thanks so much for posting this!
Just had to come back and say I made this dish and it was awesome!  Thank you for sharing the recipe!  ~Diane
afalconfan4 years ago
Excellent! It was a hit with my family. Used a 3 quart dish and 2 cups of milk (that was ample) and cut the bread in smaller pieces (more bite size).I used more cheese but then what dish couldn't use more cheese. My wife says do it again!
dulciquilt4 years ago
would it be overkill to use cream of onion soup?
Forkable (author)  dulciquilt4 years ago
Woah!  I don't know.  There's only one way to find out...
This looks yummy! I was looking for a new veggie-based dish to bring for Thanksgiving dinner. I love onions and it also looks fool-proof so I won't worry about trying to make it once before T-Day. Thanks!
reggierhy5 years ago
This looks very interesting. I am not sure if it is appealing or appalling! But I think i am going to find out. This could be particularly useful to those of us who have to watch our carbs as this looks like it would make a nice substitution for au gratin potatoes. It is a lot of onions although i guess it would not be much different from French onion soup which i do love. So i am going to try this today, although i might substitute muenster cheese. I will let you know what we think. Thanks for the idea, it is very creative and different from anything I have seen in a while.
 It does look delicious but I wouldn't count on it be lower in carbs than potatoes!  All that bread will make up for that!  ;)
Dantron4 years ago
 Is it possible to do this in a crock pot? I have a 4 quart that my girlfriend and I use and put on while away at classes. Perhaps cooking the onions first then mixing and adding the other ingredients?
mackamitsu4 years ago
good stuff,  we deleted the soy sauce, and bread, and added garlic croutons. My kids ate it up, and they aren't big onion fans.
Looks awesome.
reggierhy4 years ago
As promised earlier this month, I tried the recipe tonight, although with great trepidation, fully prepared to be let's just say unsatisfied. I was in for a big surprise! This was actually pretty damn good! Even my picky husband thought so after he got his brain wrapped around the idea that it was an onion casserole dish. He insisted it was meat, then potatoes, and finally he accepted it as it was and enjoyed it. I guess we just aren't used to the idea of eating onions as a dish (ahem unless they are battered and deep fried--that is one heck of a meal!) We loved it. i only had Italian blend shredded cheese in the house although i can see how it would be good with Swiss and i found some little Italian loaf rondelles already toasted in the bakery and it was so good. Thanks for introducing us to this new idea.
paperclip324 years ago
 so if i substitute the mushroom soup for the chicken one,i'll make a vegertarian?wow.
Forkable (author)  paperclip324 years ago
yes.  It is just that simple!
 oh.thanks then.
l8nite4 years ago
Being the only one in my family to really appreciate onions I saw this and had to try it !  I used 3 large spanish onions, a combination of swiss and pepper jack cheese, cream of shrimp soup and pumpernicol/rye swirl bread.  The substitutes where because thats what was in the pantry.
 The anticapation as it cooked and then cooled enough to eat was almost unbearable and then I got to eat it... the superlatives have not yet been coined to express my delight and FYI.. this is almost better cold !
I made this for Thanksgiving and Christmas, and now here I am, finding the recipe again (don't know where I put the printout) in June! I have a lot of onions right now, and am going to a potluck. I will try making it right before I head out the door so it will stay warm. I also used some homemade bread on it once (sliced thick) with garlic butter on top. YUM!
rosiegirll5 years ago
I would never make a comment about a recipe unless I tried it. It's a waste of everyone's time. So, I decided to try this casserole tonight. You see, I have 41 years of married experience cooking. Before that I assisted my mother in cooking for a family of eight. I know a good recipe when I see one!!!!!! Upfront, I could see that Forkable had a good one on her hands. Tonight I cooked it for dinner and this recipe is to die for! My husband sprinkled some parmesean cheese on top as if you were eating French Onion Soup and I used some of the Red Robin Restaurant seasoning on mine(Red Robin Restaurants are only in the West of the USA, I believe.) This recipe is going to be a staple for us I am sure. Good Job Forkable11..My new best friend!:-) One thought occurred to me... I placed the casserole dish on the lower end of my oven. You should place it up higher so the french bread browns. You want it crunchy. Also,it might be a bit of overkill for Thanksgiving due to the fact that both this recipe and the dressing would have bread in them but I'd make this for any other meal. My hubby and I ate seconds and we only touched about 1/3 of this as a main dish and we spent about $13.00 for ingredients. It would be economical if you are watching your $$. To would make this for a main dish, just add a can of chicken or chicken leftover from a baked chicken. Any way you try it this basic recipe is one of the best I've ever had. Thanks Forkable!
Friendly FYI re: Red Robin only in the West U.S.A. - We have Red Robin Restaurants here in Michigan, so they must be spreading Eastward. I'll have to check out their seasoning - thanks for the tip! :-)
Tendrop5 years ago
Very excellent recipe, common ingredients (although you might not have French bread just lying around the house), easy preparation, quick cooking time, and extremely delicious! The only issue was that the French bread didn't brown enough, but that may just be the oven that I used, or the French bread that I bought. 4.5/5!
ksparks5 years ago
Excellent! To make as a main dish, I would put in a large can of chicken (although the phrase "can of chicken" sounds wrong)... Thanks!
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