Smoke makes everything better, am I right? These Cast Iron Au Gratin Potatoes are smoked and then cooked in an oven, producing smoky crispy, cheesy potato goodness in every bite!

The definition of “Au Gratin” means browned with cheese or bread crumbs or both. In this rendition, cheese potatoes benefit from the added bonus of smoke and fresh herbs. Baked in cast iron, this dish easily goes from smoker to oven to table.  

  smoked au gratin potatoes

It's important to know that you'll never be able to fully cook potatoes low and slow on a smoker, the time it hits the smoker is purely for the smoke flavor. After you've gotten this dish nice and smokey for 20 minutes, you can then transition this skillet to the oven or at a higher temp in your pellet smoker for the remaining time. 

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grill girl, cast iron au gratin potatoes, cast iron skillet cooking

Smoked Cast Iron Au Gratin Potatoes

  • Author: Robyn
  • Total Time: 1 hour 40 minutes
  • Yield: 1/8 skillet, serves 8 1x


Smoking wood: oak, pecan 

Smoker temp: 250 

This recipe is done in two parts, first on low and slow in the smoker to get the smoky flavor, and then finished on high heat in the oven or on the grill on indirect to cook the potatoes. It spend 20 minutes in the smoker to get smoky flavor, and then finishes in the oven for an hour until fork tender and ready to eat.


  • 56 medium potatoes, thinly sliced with a mandolin on largest setting 
  • 3 tbsp butter 
  • 3 tbsp all purpose flour (gluten free is okay) 
  • 1 tsp sea salt (or smoked sea salt – page x) 
  • ½ tsp fresh ground pepper 
  • 2 cups 2% milk 
  • 1 cup cheddar cheese (you can use smoked cheese to add additional smokiness)
  • 2 tbsp chopped onion 
  • 2 tsp fresh thyme (a few sprigs) 


  1. Slice potatoes with a mandolin so they are thinly and uniformly sliced.
  2. Start your sauce by melting butter over low heat and gradually adding in the flour, then the salt and pepper. Stir constantly to create a roux. 
  3. Gradually add in the milk and bring to a boil. Cook for 2 minutes or until thickened.
  4. Remove from heat and add in cheese- stir until melted.   
  5. Layer the potatoes in a cast iron skillet. Once the entire bottom is covered with potatoes, layer with the sauce and onions. 
  6. Repeat with the remaining potatoes and sauce until all are finished. Try to ensure all potatoes touch the sauce.
  7. Smoke the potatoes for 20 minutes. While smoking, preheat your oven to 350 degrees (this can also be done on a grill on indirect heat).
  8. Remove potatoes from the smoker and cover with foil. Bake in the oven for one hour.
  9. Remove the foil after an hour and continue to bake for another 25 minutes or until the potatoes are fork tender. 
  10. Sprinkle with thyme and let cool before serving.  


For a truly “meat and potatoes” hearty homestyle meal, pair with smoked Meatloaf! Leftovers are great on their own but can also be repurposed into a frittata or skillet homefries for breakfast- just chop up before putting into the skillet. 

  • Prep Time: 20 minutes
  • Cook Time: 1:30
  • Category: Smoked potatoes
  • Method: Smoke/Bake
  • Cuisine: American

Keywords: cast iron smoked au gratin potatoes, smoked cheesy potatoes, smoked au gratin potatoes, pellet smoker potatoes

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Did you enjoy these Au Gratin Potatoes?  Try these other tasty dishes!

Cast Iron Grilled Mussels in a White Wine, Bacon Herb Butter Sauce

Cast Iron Pork Tenderloin with Apple Kale Chutney