Skillet Potatoes Au Gratin With Truffle Cheese

These skillet potatoes au gratin are made with thinly sliced potatoes and onion layered with truffle cheddar and mozzarella, then baked in heavy cream in a cast iron skillet. Once the potatoes are tender, the foil comes off and the cheese is browned under the broiler.

The truffle cheddar is what makes this potato gratin a little different from the usual version. It adds a deeper, earthy cheese flavour while the mozzarella melts between the layers. There is no separate roux or cheese sauce to make before assembling the skillet.

This skillet potatoes au gratin recipe makes 10 servings, so it works particularly well when I need a potato side for more than just a couple of people.

Quick Answer

Skillet potatoes au gratin are thinly sliced potatoes and onions layered with truffle cheddar, mozzarella, and seasoned heavy cream in a cast iron skillet. They bake covered until tender before the cheese is browned under the broiler.

Potatoes were a regular part of dinner when I was growing up, although they were usually prepared much more simply. Making potatoes au gratin taught me that the most important part isn’t adding more ingredients; it is getting the potato slices even enough that all of the layers become tender at the same time.

That is why I pay more attention to the slicing and doneness of the potatoes than to the clock. If a knife still meets resistance in the centre of the skillet, the potatoes need more covered baking time before the cheese goes under the broiler.

Why You’ll Love These Skillet Potatoes Au Gratin

One-Skillet Method: The potatoes are assembled, baked, and browned in the same cast iron skillet.

No Separate Cheese Sauce: The heavy cream is poured directly over the layered potatoes rather than making a roux-based sauce first.

Large Yield: One skillet makes about 10 servings for family dinners, potlucks, or holiday meals.

Distinct Cheese Flavour: Truffle cheddar adds the stronger flavour while mozzarella provides the milder melted cheese throughout the layers.

How To Make Skillet Potatoes Au Gratin

Start by grating the truffle cheddar and mozzarella and mixing them together. Having the cheese prepared first makes it easier to divide it fairly evenly between the potato layers.

Grease the bottom and sides of a large cast iron skillet generously with butter. The cream and cheese reach the edges of the pan as they cook, so don’t grease only the bottom.

Peel the potatoes and slice them thinly and as evenly as possible. A mandoline makes uniform slices easier, but a sharp knife works if you take your time. Consistency matters because noticeably thicker slices will take longer to soften.

Peel the onion and slice it into thin rings.

Arrange a layer of sliced potatoes across the bottom of the skillet. Add some onion rings followed by part of the grated cheese mixture. Repeat the layers until the potatoes, onion, and cheese have been used, making three layers in total.

Mix the heavy cream with the salt and black pepper. Pour it slowly over the assembled potato gratin so it reaches different areas of the skillet instead of collecting in one place.

Cover the skillet tightly with aluminum foil and bake for about 40 minutes. Before removing the foil permanently, insert a thin knife into the centre of the potato layers. The knife should slide through easily without meeting a firm piece of potato.

If the potatoes are still firm, continue baking them covered. The broiler will brown the cheese, but it will not reliably finish thick or undercooked potato slices.

Once the potatoes are tender, remove the foil and place the skillet under the broiler on high for 5–7 minutes. Watch closely and remove it when the cheese is bubbling with browned areas across the top.

Let the skillet potatoes au gratin rest for 5–8 minutes before serving. This gives the cream and melted cheese time to settle and helps the potato layers hold together better when portions are lifted from the skillet.

Ingredients

This gratin layers thinly sliced potatoes and onion with heavy cream and plenty of cheese, including truffle-flavoured cheese for a richer, more savoury finish.

Sliced potatoes: Form the base of the gratin. Use a very sharp knife to cut the slices as evenly as possible so they cook at the same rate.

Sliced onion: Adds a savoury layer of flavour between the potatoes and cheese and helps balance the richness of the dish.

Heavy cream: Creates the rich, velvety cream mixture that coats the potatoes and contrasts with the crisp top.

Cheese with truffles: Adds a rich, earthy flavour along with the gooey cheese layer.

Mozzarella: Adds a creamy, melty texture throughout the layers.

Butter: Use it to generously grease the bottom and sides of the cast iron skillet so the creamy cheese mixture does not stick around the edges.

Black pepper: Adds a mild bite that complements the potatoes, cream, and cheese.

Salt: Enhances the flavours of the potatoes and cheese and balances the richness of the cream.

Substitutions And Add-Ins For Skillet Potatoes Au Gratin

There is some flexibility in the cheese and onion, although changing the truffle cheddar will noticeably change the flavour that defines this particular version.

Potatoes: Yukon Gold potatoes can be used if that is what you normally buy. Whichever potato you choose, keeping the slices similar in thickness matters more than switching between common white or yellow potato varieties.

Yellow Onion: Shallots or thinly sliced leeks can be used for a milder onion flavour.

Truffle Cheddar: Old cheddar, Gruyère, or Fontina can be used when truffle cheddar isn’t available. The recipe will still be a cheesy potato gratin, but it will no longer have the truffle flavour of the original version.

Mozzarella: Another good melting cheese can replace the mozzarella. Gruyère or cheddar will give the finished gratin a stronger cheese flavour.

Heavy Cream: Half-and-half or a mixture of milk and cream can be used for a lighter version. A lower-fat dairy mixture will not be quite as rich and may leave the sauce somewhat looser.

Butter: Butter works particularly well for coating the cast iron skillet and adds flavour to the edges, so I prefer to keep it here.

Black Pepper: Reduce the amount to suit your taste. Cayenne or paprika can be added when you want a different flavour or some heat, but they are additions rather than direct replacements for black pepper.

Salt: The amount can be reduced depending on the saltiness of the cheese you are using. Leaving it out completely may make the potatoes taste flatter.

Expert Tips, Serving And Storing Suggestions For Best Results

Tip #1: Keep The Potato Slices Even: Uniform slices are more important than making them paper thin. Thick and thin slices mixed together can leave some potatoes tender while others remain firm.

Tip #2: Test The Centre Before Broiling: Insert a thin knife into the middle of the skillet. It should pass through the potato layers easily before you remove the foil and brown the cheese.

Tip #3: Watch The Broiler Closely: Cheese can move from lightly browned to overly dark fairly quickly under high heat. Stay near the oven during the final few minutes.

Tip #4: Let The Gratin Rest: Give the potatoes 5–8 minutes after they come out of the oven. The cream and cheese settle slightly during this time, making the portions easier to lift from the skillet.

Serving Suggestions

Skillet potatoes au gratin are a rich potato side, so they pair well with simply prepared meats and vegetables.

Serve them alongside Roast Turkey With Spices for Thanksgiving or Christmas dinner when you want something different from mashed potatoes.

They also work well with Dutch Oven Hungarian Pot Roast or another slow-cooked beef dinner because the creamy potatoes balance a savoury roast and gravy.

For a simpler meal, serve the potato gratin with Air Fryer Roast Chicken and a green vegetable or salad.

If you would rather have a crispy potato side instead of a creamy one, my Crispy Baked Potato Hash is another way to prepare potatoes for dinner.

Storage And Reheating

Cool leftover potatoes au gratin before transferring them to an airtight container. Store them in the refrigerator for up to 3 days.

Individual servings can be reheated in the microwave. Larger amounts can be reheated in the oven until heated through.

For longer storage, cool the gratin completely and wrap it well before freezing for up to 3 months. Thaw frozen potatoes au gratin overnight in the refrigerator before reheating. The potatoes may be somewhat softer after freezing and thawing than they are when freshly made.

The main things to watch with these skillet potatoes au gratin are the thickness of the potato slices and their tenderness before the cheese goes under the broiler. Once the potatoes are soft, the truffle cheddar, mozzarella, cream, and browned cheese top finish the dish without requiring a separate cheese sauce.

If you have made potatoes au gratin with a different cheese, what combination did you use?

Meet Amber

I’m the home cook and recipe creator behind A Cents For Cookery. I learned to cook growing up off-grid in Northern Ontario, where meals were made on a woodstove and preserving, baking, and making ingredients stretch were part of everyday life. Here I share practical family recipes, homemade baking, vintage-inspired cooking, and the kitchen knowledge I’ve picked up over the years to help you make the most of the food you have.

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