The almighty humble potato makes a stunning dish called Potatoes Au Gratin, the French would call it a few different names depending on what region the dish is originating from. There are many variants of the name of the dish, including Pommes de Terre Dauphinoise, Potatoes à la Dauphinoise & Gratin de Pommes à la Dauphinoise.

What does Au Gratin mean? Answer: To grate, usually with breadcrumbs or grated cheese. Classicly using Gruyere cheese.


Did you know there are over 200 varieties of potatoes?

Did you know there are over 200 varieties of potatoes?  Of the 200, there are 7 categories they fall into, russet, red, white, yellow, blue/purple, fingerling and petite. I’ve never seen a blue potato? Have you? Please leave a comment below and tell me all about them. Thanks


Definition of Dauphinois
adjective: dauphinoise
  1. (of potatoes or other vegetables) sliced and cooked in milk, typically with a topping of cheese.

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Today’s recipe is all about tradition and the traditional preparation of Potatoes Au Gratin. This recipe could be looked at as a simple dish, yet also elegant with great depth of flavor that comes from a traditional Bechamel being prepared in the classic French way. Often a Bechamel sauce is referred to as a “White Sauce”, and they would be correct. But remember, a White Sauce is not a Bechamel. For a White sauce to become a Bechamel there are certain steps and flavorings that must be used in order to become a traditional Bechamel Sauce.

The Bechamel Sauce.

I believe this step is sometimes overlooked in the way of importance. Potatoes Au Gratin is a classic preparation of potatoes sliced thinly and covered in a creamy traditional Bechamel sauce. The bechamel sauce is the key to this amazingly simple, yet elegant potato dish.

Here’s our article outlining everything you could need to know about making a proper Bechamel Sauce. I would like for you to watch the video as well. You’ll be able to see the movement/motions that goes into making a classic French sauce and even more important, the timing. Sauce making is all about good techniques, yet the key is “Timing”.

Here’s our video covering making a Classic Bechamel Sauce

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Great ! We now know everything that it takes to make a traditional Bechamel sauce. If you haven’t experienced this sauce made the Classic French way you’re going to be pleasantly surprised. The flavoring really takes the sauce up a notch.

Now on to the potatoes. Wow, with 200 possible types of potatoes how do we begin to pick which type to use? I have an answer to this type of question I think almost always holds up. You should use the kind you like. Just like cooking with wine, you should cook with the type you enjoy. Yet, dealing with potatoes there are characteristics which can help with the finished dish.

 Idaho Russet Potato


  1. an odorless tasteless white substance occurring widely in plant tissue and obtained chiefly from cereals and potatoes. It is a polysaccharide that functions as a carbohydrate store and is an important constituent of the human diet.

Potatoes have an abundance of nutritional value, including a high level of macronutrients, vitamins & minerals. One of the potato’s greatest nutritional offerings is its carbohydrate content. Potatoes contain both simple and complex carbohydrates, as well as a substantial amount of dietary fiber. Most of the carbohydrates in potatoes are complex carbohydrates, called starch. Potatoes also contain simple sugars, with glucose being the most prevalent.

Types of Potatoes for Potatoes Au Gratin


First off we have the Idaho Russet Potato

russet potatoes

-russet-skinned with white flesh. They’re what we typically imagine when we think of potatoes. They have a neutral potato flavor, a fluffy, creamy and soft texture, and are best for baking, mashing and making French fries. They’re also very absorbent, work great paired with butter and cream — think mashed potatoes.

Yukon Gold Potatoes

yukon gold potatoes

Also, know as “Chef White” potatoes

– finely flaked yellowish-white skin with light yellow flesh. They’re bright, vegetal and slightly sweet, with a smooth, slightly waxy texture and moist flesh. They’re best for boiling, baking and making French fries. They’ll also stand up well to grilling, pan frying & roasting.

Type of Potato NOT to Use

Red Bliss — Waxy

Red Bliss — Waxy

– bright red skin with creamy white flesh. They’re slightly bitter and have a firm, moist and waxy texture. They’re best for soups, stews, boiling, roasting, potato salad and casseroles, and worst for mashing.

Making the Potatoes Au Gratin & the Classic Bechamel Sauce

First thing, Peel and slice your Russet potatoes. The reason we start with the potatoes is “Timing”. When working in the kitchen “Timing‘ is everything. This is a skill a lot of cooks struggle with. Here at Butter-n-Thyme “Timing” is a focal point in our lessons. Sure we teach you how to make the recipes in the articles, but underneath the goal is to empower all our readers with solid culinary information and training, skills, tips & tricks. Be sure to wash off the potatoes before peeling. In the photo below, I only cut off some of the outside peel. This helps with presentation. If you peel the potatoes your dish could appear plain to some degree, a lot of white space, but that also could be a good thing. Just something to consider. Plus, the potato skins is where most of the health benefits come from.

Use a normal peeler to create the striped potato cuts. Just peel down the length of the potato and alternate.

sliced russet potato

Chef Tip: Potatoes oxidize and turn color when left exposed to air. Notice in the photo above the potato is put back together to reduce surface area. Resulting in almost zero oxidization. You could place them in a bowl filled with water as well.


Next step is making the Bechamel Sauce


First things is “Mise en Place” (MEEZ ahn plahs) .  Prepping all the ingredients needed. Weighted out and ready to go. If you wait to measure while making the sauce your “Timing” isn’t going to be perfect. Always measure and weight out your ingredient before starting cooking. #EveryTime

Add 4 tablespoon butter and melt. Then add 3 tablespoons of flour. We are making a Roux. Which by definition a Roux is equal parts butter and to flour. Since we are making a Bechamel sauce we will be using a little less flour. The fat in the Milk would be the reason. This also allows for a longer time for the sauce to tighten up/thicken while the flavors develop.

Cook Out the Flour – exposing the flour to the butter over heat will help prevent graininess in the sauce by moistening the flour

roux-adding flour and butter and cooking out flour

While stirring, add in 1/3 of the Milk over medium-high heat.

Once the sauce starts to thicken, add the remaining Milk and keep stirring.

whole milk measure out to 2 cups 1/4


Bring the sauce up to a soft bowl. Do not scald the Milk

adding milk and bringing to a soft boil

Using a micro planer shave in fresh Nutmeg. Around 1/8 Tsp

grating nutmeg into bechamel sauce

Prep the Onion

When you’re prepping the Potatoes, Prep the Onion then. Do not wait.

Cut the Onion in Half and remove the peel. Take 7 Cloves and remove the tops, the small ball that is attached. The flavor profile from the tops is too strong of a flavor. ( Learned that in culinary school & holds true )

placing cloves in half onion for bechamel sauce


Next place the Onion in the sauce and cover to infuse flavor. The “Timing” is right after you finished stirring in the second addition of Milk and reached a soft boil. Turn off the Heat before adding the Onion, then cover and wait around 5 minutes. Take a taste. If you’re happy great. If not, allow more time to impart flavor. If the sauce tries to thicken too much just add a little bit more Milk to thin the sauce out. Season with salt to taste. add small pinch.

place onion in bechamel sauce to flavor the sauce


Building the Classic Potatoes Au Gratin

First, cover the bottom of the casserole dish with Bechamel sauce then add a small layer of cheese

adding bechamel and cheese to bottom of casserole dish

Next, add two layers of sliced potatoes in a shingled pattern

laying out the potatoes in a shingled pattern


Add Salt and Pepper and cover with a layer of Cheese and Bechamel sauce

adding bechamel sauce to the first layers of potatoes


Keep repeating process till you’ve reached the level you’d like for your casserole dish. Remember, don’t overfill with bechamel sauce. That would affect your presentation.

cover with remaining bechamel sauce


Place on a cookie sheet. The casserole could bubble over. Another reason to not overfill with Bechamel sauce

potatoes au gratin on cookie sheet ready to bake


Bake for 45 minutes to one hour. Test with a fork for doneness

bake on cookie sheet for one hour


When you’ve reached the correct doneness, turn on the Boiler and brown the top of the Au Gratin.

Crack the oven door and keep an eye on it.


Wallah & Bon Appetit

classic potatoes au gratin

Watch How To Make a Classic Potatoes Au Gratin

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classic potatoes au gratin

Classic Potatoes Au Gratin

Creamy cheesy potato recipe that everyone loves
5 from 4 votes
Print Pin Rate
Course: Casserole
Cuisine: Classic French
Prep Time: 6 minutes
Cook Time: 1 hour
Total Time: 1 hour 6 minutes
Servings: 8 Servings
Author: Steven Pennington


Bechamel Ingredients

  • 3 Tbsp All-Purpose Flour
  • 4 Tbsp High-Quality Butter
  • 2 1/2 Cups Whole Milk / plus more to help control the thickness
  • 7 Cloves
  • pinch Nutmeg
  • 1/2 Onion / kept whole/ cloves attached
  • 1/2 tsp Thyme
  • 1/2 tsp Minced Garlic

Potatoes Au Gratin Ingredients

  • 4 Medium sized Potatoes
  • 1 1/4 cups Gruyere Cheese or Swiss /shredded
  • Salt & Pepper - to taste
  • 1/2 Onion Julianne Onion / Julianne cut onion, long thin slices.



  • Flavored ROUX: First, melt butter over medium-high heat, then add the garlic and toast, following with the flour and coat all the flour in the butter.
  • "Cook-Out" the flour. Allow the flour to absorb the butter. This will help ensure the bechamel sauce will not be grainy.
  • Next, add in 1/2/half of the milk and stir constantly. The sauce will try to thicken. Add the remaining milk at this point, little by little. Keep stirring. Allowing the milk to come to a soft boil. (Soft boil means the bubbles are breaking the surface, but not a full boil)
  • Once at a soft boil, turn off the heat. The sauce will thicken. If the sauce gets too thick for your purposes add a little more milk to thin out the sauce. Remember the heat activates the Roux and thickens.
  • Add the Nutmeg, to taste. Stir and incorporate
  • Next, add the "half" Onion with the Cloves attached to the onion.
  • Cover the pot for a few minutes to allow the flavors to develop.

Prepping the Potatoes

  • First, wash off the potatoes well. Using a mandolin or sharp knife, make thin slices. The thickness choice is up to you. I suggest 1/8 inch slices. Remember the potato skin is where most of the health benefits reside. I took a peeler and removed only part of the skins. Made peeled stripes going down the length of the potato in an alternating pattern. It helps with the presentation. See Video Above./Below

Making the Potatoes Au Gratin

  • First, pour Bechamel sauce covering the bottom of your casserole dish. Using glass-bakeware is suggested for even cooking. The bechamel sauce acts to protect the potatoes from burning and sticking. Next, add two layers of potatoes. Lay the potatoes out with each potato slightly covering the last potato. Shingle pattern. Then add a layer of cheese and cover with Bechamel sauce. Add a small amount of salt & pepper, cheese of your liking and julienne cut onion for more flavor and texture. Repeat the process till you've filled your bakeware to the desired level. Add the remaining Bechamel sauce, allow for the potatoes to stick out a small amount. Don't drown the potatoes in sauce, helps with presentation. Cover with more cheese and place on a cookie sheet to prevent bubbling over.


  • Preheat Oven 375 (could do 400) both work
  • Cook for 45 to one-hour plus or till done. All ovens are different and the depth of everyone's cookware will be different.
  • Test for doneness. Poke with a fork. If soft enough, turn on broiler to brown the top. Be sure to keep on eye on this process as the potatoes au gratin could burn. Crack the oven door so you can see what's happening.
  • Allow to cool for 5-10 minutes and enjoy it.