Potatoes Au Gratin – Overthinking Classics

Potatoes au gratin - overthinking classics
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It’s that time of year again. Here in Canada, Thanksgiving is just a little over a week away, so let the holiday content begin. From here on out, this blog will be home to a parade of festive and company-friendly appetizers, mains, and desserts. But don’t worry, there will still be plenty of breather meals along the way. And if that’s what you’re currently hungry for, take a peak at the Tajín Shrimp Bowls I posted earlier this week. But today, we’re kicking things off with a potato dish because at this time of year potatoes reign supreme. Potatoes au Gratin is always a welcome sight at any holiday table. So we’re giving it the Overthinking Classics treatment and exploring this iconic dish from every angle.

Potatoes au Gratin

Potatoes au Gratin is an interesting dish. It made me question a lot of things culinarily speaking. This side seems to carry a fair amount of opinions and preferences. But its origins are crystal clear. Potatoes au Gratin or Gratin Dauphinois was first served during a state dinner held by Charles-Henri, the Duke of Clermont-Tonnerre and Lieutenant-general of the Dauphiné region in France in 1788. In its barest form, the dish consists of potatoes sliced “slightly thicker than a penny” cooked in a cream sauce in a shallow vessel rubbed with butter and garlic. The dish is sometimes topped with cheese and/or breadcrumbs and broiled. And this is where the biggest bone of contention lies.

Potatoes au Gratin

Does Potatoes au Gratin have to contain cheese? Well, some purists say no while others claim the cheese is the only thing that separates gratin from scalloped potatoes. But I was shocked to learn, a gratin doesn’t have to include cheese. Technically anything finished with a browned crust qualifies as a gratin, which stands to reason given the etymology of the word. Gratin comes from the French word “gratine”, which translates to “crust” or “skin”. This crust can be achieved using breadcrumbs, cheese, egg, butter, or a combination of any or all of these ingredients.

Potatoes au Gratin

If you’ve ever had scalloped potatoes, which do not include cheese, you probably noticed a browned bubbly surface that forms through the caramelization of the cream and butter in the sauce. That is technically a gratin. And scalloped potatoes may actually be closer to the original Gratin Dauphinois than the cheesy gratins that are much more common today in North America. Does that blow your mind? It kind of blows my mind. But with today’s Potatoes au Gratin I stay true to my North American sensibilities and leave scalloped potatoes and potatoes au gratin separated in their respective camps. The gratin below contains a fair amount of cheese. And it’s Gruyere! Yeah, we really splashed out for this one.

Now, this dish is incredibly simple to put together. I complicate things a little by building roux but that roux also allows you to trim back the amount of cream you use. I prefer this approach because I find gratins made solely with cream overwhelming. Plus, this gratin is for a holiday table where it never pays to tap out early. We can’t have gratin taking up all of your stomach’s real estate.

Potatoes au Gratin

What makes this gratin so holiday-friendly is not just its potato content and general cozy flavor profile. It’s that it can be made ahead. Yes, you can make this gratin, and bake it right up to the cheese and crumb coating portion of the recipe up to three days in advance. Yeah, so there’s very little day-of fussing. And in order to get that bubbly top, you just have to turn on the broiler for less than 5 minutes. So it doesn’t matter what your oven was doing or what temperature it was at just prior to broiling your gratin. Honestly, this dish will save you a lot of holiday-related grief.

So without further ado, here is my overthought recipe for Potatoes au Gratin. It’s rich and creamy but not overwhelming, so you can and should have a slice of pie immediately afterward. And let’s face it, we’re all here for the pie anyway.


Potatoes au gratin - overthinking classics

Potatoes au Gratin

This rendition of Potatoes au Gratin features thin slices of potato cooked until tender in a rich bechamel and topped with a golden lid of melted Gruyere cheese and crisp breadcrumbs.
Prep Time 30 minutes
Cook Time 1 hour 20 minutes
Course Side Dish
Servings 8


  • 1 10" gratin dish
  • 1 skillet
  • 1 small saucepan
  • 1 mandoline
  • 1 Food Processor


  • 2 cups 2% milk
  • 4 shallots quartered
  • 2 cloves garlic smashed
  • 1 tbsp fresh thyme leaves **
  • ½ cup panko breadcrumbs
  • 2 tbsp unsalted butter
  • 2 tbsp all-purpose flour
  • 1 tbsp Dijon mustard
  • 1 tsp salt
  • ½ cup heavy cream
  • 2-3 Russet potatoes *** sliced thin on a mandoline
  • 150g (5oz) gruyere shredded
  • fresh sage leaves to garnish


  • Pour the milk into a small saucepan. Add the shallots, garlic, and fresh thyme leaves. Bring the milk to the verge of boiling, then reduce the heat to a simmer. Simmer the milk for 15 minutes or until the shallots are tender. 
    2 cups 2% milk, 4 shallots, 2 cloves garlic, 1 tbsp fresh thyme leaves **
  • While the milk is simmering, preheat the oven to 325°F. Grease a casserole or gratin dish with butter and set it aside.
  • Pour the breadcrumbs into a dry skillet and place over medium heat. Toast until golden, shaking the pan frequently. Transfer the breadcrumbs to a bowl and set them aside.
    ½ cup panko breadcrumbs
  • When the milk is done simmering, take it off of the heat and transfer it to a food processor. Blitz the mixture until smooth. Pour the mixture into a large measuring cup and set it aside.
  • Place the butter in a small saucepan over medium heat. When the butter melts add the all-purpose flour and whisk the two together to form a roux. Slowly whisk the milk mixture into the roux, making sure each addition is fully integrated before adding more. 
    2 tbsp unsalted butter, 2 tbsp all-purpose flour
  • Once all the milk is in, add the mustard and salt. Stir to combine. Take the sauce off of the heat and whisk in 1/2 a cup of cream.
    1 tbsp Dijon mustard, 1 tsp salt, ½ cup heavy cream
  • Arrange the slices in the dish you prepared earlier. Fan the potatoes out until they cover the bottom of the dish. Sprinkle them with salt and pour a third of the sauce on top. Add a little of the gruyere but be sure to reserve 100g for the top. Repeat until you have three layers of potatoes finishing with the final third of the sauce. Don't put cheese on top of the final layer of sauce.
    2-3 Russet potatoes ***, 150g (5oz) gruyere
  • Cover the potatoes with tin foil and transfer them to the oven. Bake for 65-75 minutes or until the potatoes are fork tender.
  • When the potatoes are done, take them out of the oven and turn on the broiler. Remove the foil and sprinkle the surface with the cheese, followed by the panko breadcrumbs. Return the potatoes to the oven and broil until the cheese bubbles. Keep a close watch on the gratin and rotate the dish to ensure it browns evenly.
    150g (5oz) gruyere
  • Take the potatoes au gratin out of the oven and let cool for 10 minutes. Garnish with fresh sage leaves and some fresh ground pepper and serve immediately.
    fresh sage leaves


** If you don’t have fresh feel free to use dried thyme. 
*** Slice your potatoes “no thicker than a penny”. Or at least that’s what English food writer Elizabeth David advises and who am I to argue?
Keyword breadcrumbs, gruyere, potatoes

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