
Potato Gratin, or Potato Au Gratin, is one of the coziest casseroles of all time. Layers of sliced potatoes are smothered in a rich, creamy cheese sauce and then baked in the oven until bubbly and golden. It’s homey yet thoroughly indulgent.
To take the classic gratin up a notch, I’d like to present Salmon Potato Gratin (鮭ポテトグラタン). This elevated version incorporates an easy, all-purpose salmon flakes but still has all the amazing flavors. Don’t miss it if you love a good casserole for your Sunday dinners or holiday table!
Why You’ll Love This Salmon Potato Gratin
- Rich, creamy, and satisfying!
- Super easy to put together.
- Comforting dish all year round.
- Great for make-ahead and reheat well.

Tips for Getting the Right Ingredients
Potatoes
For the right texture of potato gratin, you must use Russet potatoes. This variety has the most starch and makes the creamiest sauce and tender texture.
Cream (+ Milk)
For the creamiest, velvety sauce possible, I highly recommend using 100% heavy cream. However, I know many of you wish to make it “healthier”, so I will leave it up to you. For a lighter sauce, you can use half-and-half or milk. For this recipe, I went with the 1 (milk) : 3 (cream) ratio.
Homemade Salmon Flakes (Make-Ahead)
Salmon flakes are basically salmon that have been baked, then flaked into pieces and pan-fried with seasonings until they are dried for later use. In Japanese cooking, we use salmon flakes as toppings or as a versatile add-on in many dishes. You can get the salmon flakes recipe here!

One of the easiest adaptations of Salmon Flakes in western cooking is to pair it with creamy dishes; whether it’s creamy mushroom pasta or in this Potato Au Gratin. In addition to Omega 3, salmon flakes lend substance, rich texture, and flavor to the overall dish.
Parmigiano Reggiano Cheese
I recommend Parmigiano Reggiano for grated cheese in this recipe. If you have other options, feel free to use what you have. But if you are going out to shop for the recipe, try finding Parmigiano Reggiano. It has a pronounced flavor that works incredibly well with gratin dishes.
Seasonings
I used Kosher salt, freshly ground black pepper, and dried thyme. If you have fresh thyme, you can double the amount. Feel free to use other herbs such as parsley or leave it out.
Panko Breadcrumbs
Japanese-style gratins ALWAYS get a generous sprinkle of panko breadcrumbs on top for a nice crunch and golden topping! As a kid, the charred top layer of gratin was my favorite, and I always picked the extra burnt piece on the side of the baking dish!

Super Easy 3 Steps to Make Salmon Potato Gratin
This dish is so easy to make. Most of the work is on cutting the potatoes into thin slices!
- Peel and slice the potatoes.
- Layer potatoes, salmon, cream, and cheese.
- Bake in the oven!
Yes, that’s really it.

What to Serve with Salmon Potato Gratin
Creamy and rich gratins go well with any baked/roasted/pan-fried meat dishes. Of course, you can always enjoy it as a standalone main dish!
- Japanese Pork Roast
- Grilled Kurobuta Pork Chops with Miso Sauce
- Reverse Sear Steak with Smoked Garlic
- Hambagu (Japanese Hamburger Steak)
- Smoked Miso Butter Turkey Breast

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Salmon Potato Gratin
Ingredients
- ½ cup whole milk
- 1½ cups heavy (whipping) cream
- 3 russet potatoes (830 g, 1.8 lbs)
- 1 cup Parmigiano-Reggiano or Parmesan cheese (3.4 oz)
- 1⅓ cups Homemade Salmon Flakes (Make my homemade recipe or purchase it from a Japanese grocery store)
- 2 Tbsp panko (skip for gluten-free)
For the Seasonings
- 1 tsp Diamond Crystal kosher salt
- ¼ tsp freshly ground black pepper
- ¼ tsp dried thyme (or double the amount if you use fresh thyme; more for serving; optional)
Instructions
- Gather all the ingredients. You will need one 8- x 8-inch (20- x 20-cm) baking dish.
- Preheat the oven to 350°F (177ºC) and set an oven rack in the middle position. Combine ½ cup whole milk and 1½ cups heavy (whipping) cream. Grease an 8-inch (or 2-quart) baking dish with butter.
- Peel 3 russet potatoes and cut them into ⅛-inch (3-mm) uniform slices. Some people like to use a mandoline slicer and get very thin slices. I personally like them to be slightly thicker. Tip: If you are making ahead, soak the potatoes in water for 10 minutes to prevent them from changing colors.
- In a large mixing bowl, add the potatoes, 1 tsp Diamond Crystal kosher salt, ¼ tsp freshly ground black pepper, and ¼ tsp dried thyme.
- Toss everything until evenly coated. Arrange some of the potato slices in a single layer, overlapping slightly, on the bottom of the baking dish. This baking dish is shallower than other baking dishes I have. Therefore, I made 2 sets of layers and used half of the ingredients for each layer. You may be able to make 2–3 layers.
- Evenly distribute half of 1⅓ cups Homemade Salmon Flakes over the potatoes, then sprinkle half of the 1 cup Parmigiano-Reggiano or Parmesan cheese on top.
- Pour half of the cream mixture over top. Repeat with remaining potatoes and Salmon Flakes.
- Sprinkle the remaining cheese and cream.
- Sprinkle a generous amount of 2 Tbsp panko over the top.
- Place in the oven and bake, uncovered, for about an hour, or until the potatoes are tender and golden on top.
- Check the doneness by inserting a skewer. If you prefer a nice char on top, turn the broiler on High for 1 to 2 minutes. Keep an eye on the baking dish so the top won’t get burnt. Remove the baking sheet from the oven and set aside for 10 minutes before serving. Sprinkle with fresh thyme, if using, and then serve.
Doubling the Recipe
- For the potatoes to cook more evenly, I recommend making 2 baking dishes rather than 1 large baking dish.
Notes
Nutrition
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