Potato and Caramelized Onion Gratin

This is for all the last minute Thanksgivingers out there. You know who you are. The ones that are just barely planning things out. Maybe even the ones who haven’t thought about it at all, not for a second. This post is a last minute salvation to all those people out there that are experiencing a cry for help. HELP. I’m here to help, don’t worry. I can’t make your turkey for you (although I wish I could), but how’s about another side dish idea? Those always come in handy, right? Just yesterday I gave you a Sausage and Mushroom Wild Rice post that will be perfect right there on your dinner table next to your turkey. This potato dish is a nice alternative to mashed potatoes or even served with mashed potatoes. Why choose either/or when you can have both?! I’m totally okay with the idea of eating potatoes on top of potatoes because if you recall, I have an undying love for this vegetable. This side dish will go great with the rice and turkey you already have planned out for the big gathering. And if you haven’t bought your turkey yet, well then at least you’ll have rice and potatoes on the table. I wouldn’t mind that. Sounds like a perfect meal to me.

Sometimes you just need a simple recipe to keep up your sleeve for all those days when you find yourself in a cooking rut or bind. A quick and easy dish that will wow someone’s face off. Like ka-POW, there goes your face. It was just wow’d off. We all need recipes like that because life happens, even when we don’t want it to, and you don’t know what to do about it when it does. Perhaps you’ll get unexpected guests over for dinner one night (RUDE), or maybe you just need to whip up something in a hurry because you have a million other things to do and the last thing you want to do is slave away in the hot kitchen. Well, make this gratin and you’ll be good to go. Start incorporating it into your cooking repertoire because I can guarentee you that you’ll fall in love with it. You’ll be amazed on how fast and easy it is to put together, yet it’s packed with so much flavor. Make a quick sandwich and serve this alongside it. Grill up a piece of fish and eat it with a large helping, or two, of this awesome dish. I won’t tell anyone, I mean after all, what are friends for? This year, not that much different from every year really, I’m most thankful for potatoes. For being so incredibly delicious and easy to to cook with. This Thanksgiving, it’s all about you. Now let’s get cooking.

This recipe, much like the last one, is super simple to make. There is minimal to do on your part which is perfect for Thanksgiving because you get to just whip it up as fast as you can and then allow the oven to do all the work for you. It doesn’t get any better than that friends.

We start by caramelizing a few onions. I just use a few large yellow onions. Slice the ends off, cut in half, peel and then cut into thin strips.

Heat a skillet over medium-high heat, and toss in a couple tablespoons of butter. Allow to melt completely.


Add the sliced onions.

**Note: It might seem like a lot of onions at first, but add them to the skillet and they cook, the onions will break down.**

Cook, stirring frequently until they are soft and translucent.

Season with salt, black pepper and a bit of sugar.


**Tip: Adding sugar to the onions helps the caramelizing process. Onions have natural sugars already, but adding a bit of granulated sugar speeds up the caramelizing. After all, this is supposed to be a fast recipe remember?**


Continue to cook the onions until caramelized and evenly browned. Make sure to keep an eye on them as they cook, stirring every so often because they can burn rather quickly if you’re not paying attention.

You can remove the skillet from the stove and allow to cool down slightly.

In the meantime, let’s get the cream ready.

We’re going to heat the cream through and infuse it with a few great flavors.

Now I’m going to say it right off the bat, this isn’t a healthy dish. I never claimed it to be. I mean we all know that potatoes gratin is very rich. With that being said, yes we are going to use cream for this. It’s Thanksgiving, let’s just have fun. Let loose. Eat cream. No big deal.

No you cannot use skim milk, it won’t be the same. Trust me on this. I’ll work with you here and say that if you really must, you can use half and half. But that’s it. That’s where I draw the line.

So pour that cream into a pot. You know you want to. Let’s be bad together. Everyone’s doing it.


Toss in a couple dried bay leaves, 2 or 3 garlic cloves and a few sprigs of fresh thyme, stems and all.


Heat the cream over low heat, making sure to not boil it, allowing the flavors to develop.

**Tip: Heating the cream will allow the potatoes to cook faster in the oven because you won’t have to wait for the cream to get hot. Plus the heat develops the flavors of the garlic and herbs. That’s what we’re looking for.**

It should cook for about 4 to 6 minutes on low.


In the meantime, let’s get the potatoes ready.

Peel a few russet potatoes. It needs to be russet because they hold better in the oven. Red and yellow potatoes would mush up too quickly.

We’re going to use a special tool for this. It’s called a mandolin, you can buy it online or at most kitchen supply stores. If you have a B3 (Bed Bath and Beyond) in your area, or a Sur La Table, you’ll definitely find them there. Of course they range from super expensive and fancy to the bare minimum and low in price. I got the bare minimum low in price. As long as it slices, that’s all that matters to me. I don’t need to be spending lots of money on a gadget I don’t use often. So it’s just a cheapy plastic one.

These tools are very dangerous because the blades are really sharp and you’re basically just sliding the potatoes back and forth with your bare hand over the blade.

**Tip: Don’t try to get every last bit of the potato used, once you get towards the end you can stop and just discard the end. Why risk cutting yourself for a little piece of potato?**

It slices the potato into thin even slices. You can adjust the sizes but you want it super thin so it cooks faster.

**Tip: Add the potato slices into a large bowl of cold water. This will prevent discoloration but also will remove excess starch.**


Okay so our onions are caramelized and cooled. Our cream has steeped with the goodies and is warmed through. The potatoes are sliced. The cheeses are grated. We’re now ready to assemble.

You’re going to need to grab a deep medium baking dish.

Don’t worry about greasing it, it’ll be fine without.

Start with a layer of potatoes. Place them on top of each other forming rows.

Top with some of the caramelized onions.

Cover with a few ladles of the warm cream, making sure to not add the bay leaves, thyme sprigs or garlic cloves.

Sprinkle grated Romano cheese on top.

Repeat with another layer of potatoes.

Top with more of the caramelized onions.

Add more cream and sprinkle with Romano cheese once again.

Depending on how deep your baking dish is, you can continue in this manner for another two layers until all the onions and cream have been used.

Then top with a final layer of potatoes. Using a spatula, press down on the potatoes, the cream will creep up and around, that’s okay. Sprinkle with more Romano cheese and freshly shredded gruyere cheese. For a finishing touch, crack a bit of black pepper right on top of the cheese.

Bake in a preheated 375° oven for about 35 to 40 minutes until the potatoes are tender, the cream is bubbling and the cheese on top has browned. You can pop the dish under the broiler for a few seconds to really brown the top at the very end.

Remove from the oven and allow to sit for about 20 minutes before serving. This will give it a chance to set. Sprinkle with chopped chives and parsley for garnish.

Can you really look at this and tell me that you can resist? I think this is a must for your Thanksgiving feast. If you already planned out your entire meal, I think you need to include this dish because your guests will definitely love it. Start rethinking one of the other sides and go to the market to get the ingredients you need in order to make this.


The great thing about this dish is that it reheats really well. You can definitely make this the day before, allow it to cool down completely. Cover it with foil and store in the fridge. Then, half an hour before the big meal, you can pop the dish in the oven (with the foil) and reheat. That’s one less dish to stress out about.


I’ve done all I can do to help you out this Thanksgiving, with these last minute side dish ideas. The great news is that they are super easy to whip up. The even better news is that they are crazy delicious. I want to say it was a lot of work in making these and posting them as fast as I possibly could, but in reality it wasn’t that much work and eating both of them while doing it, definitely helped. I hope that this has saved at least one of you, if not for the big day, then for any other day. Give these recipes a shot and let me know what you think. Don’t forget about that Sausage and Mushroom Wild Rice. Above all, thank you for supporting the blog, for reading it and for leaving your comments and feedback. I really appreciate you all. This year, I’m ever so thankful for all of you. For keeping me floating and allowing me to do what I love. I hope you have a safe and fun holiday and I hope you eat until you cannot eat anymore. That’s what I’m planning on doing. No regrets. Just good times with family and friends. Happy Thanksgiving!


  1. avatarkrystal says

    This looks amazing. I also have a deep, undying love for carbs and especially potatoes. I think this needs to make an appearance at my friends Christmas party!

  2. avatarCarol says

    I’ve had a lifelong love affair with potatoes too! So I understand completely. Just reading this inspires me to be a better cook. I will be making this recipe. Thank you so much for sharing the inspiration and the recipe. Hope you have a wonderful Thanksgiving.

  3. avatarPat Kaiser says

    I’m beginning to question my decision to follow your blog… if I continue to read and then attempt to recreate your recipes, I will weigh 500#!!! JK!! Seriously, I’m enjoying reading, enjoying the pictures and enjoying coming close to recreating your recipes!! And the best part, enjoying eating, wait, savouring those recreations!!! As for gaining the weight, I just add on a couple more miles of walking per day… no prob!!

  4. avatarLinda Piotrowski says

    My husband and I love Carmelized onions and potatoes, too! This recipe looks fabulous. We are going to be guests for Thanksgiving but I plan to make this for Sunday’s dinner. Thanks for taking the time and your work to post this. Happy Thanksgiving.

  5. avatar says

    Ok I did not see this recipe until just now but I made pretty much this dish for our Christmas feast (alongside a ham that was at least as large as myself) and it is SO good! And of all my dishes, it was the one thing we finished off…. sadly, no leftovers for me fo breakfast. Instead of caramelized onions, I caramelized fennel and layered that with the potatoes. Rockin.

    Your method is perfect (warm cream, layering, cheese etc) and I absolutely used heavy cream, but I confess I cut it down a bit (nearly half) with chicken stock. It was still super silky and rich. Bravo on this my dear! Beautiful photos too!

    Also — I thought I would save time/try to be clever and make this the day before but NOT cook it and chill it. I just chilled it raw. Obviously, the top layer of potatoes grayed terribly. So, I hid them under more cheese. What?…

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