Smoked Au Gratin Potatoes

By James Kimble October 15, 2026 5 mins read 113 Views

These smoked au gratin potatoes are an upgraded version of the classic comfort food. This recipe uses simple, flavorful ingredients to create a deliciously creamy side dish.

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What is the difference between au gratin and scalloped potatoes?

Few things are better than a hearty serving of creamy au gratin potatoes. It’s warming, comforting, and very satisfying. However, cooking this dish in the smoker takes it from good to downright fantastic. I was skeptical at first, but after taking my first bite, I was impressed. You can’t beat the light smoky flavor, crisped edges, and all that cheesy, buttery goodness. These smoked au gratin potatoes are perfect for the holidays and pair well with turkey, rib roast, and leg of lamb!

What is the difference between au gratin and scalloped potatoes?

Both of these potato casseroles contain a sauce made with milk or cream, butter, and flour. Au gratin has cheese, which creates a tasty golden brown crust. Scalloped potatoes are recognized for their browned, scalloped edges.

How long does it take to cook au gratin potatoes in a smoker?

It takes about 1 hour at 350 degrees F. Aim for 2 hours at 275 degrees F if you’d like the au grain potatoes to have a robust smoky flavor.

Choosing the right potatoes

Medium-sized russets work well for smoked au gratin potatoes. They have a fair amount of starch and a delicious buttery taste. You can also use large red potatoes. Slice the potatoes using a mandolin or your food processor. I recommend scrubbing them with a vegetable brush under cold water and drying them well with paper towels before slicing.

Equipment

9 X 9 pan (cast-iron, grills safe stoneware, or aluminum)
Medium saucepan
Whisk
Spatula
Large bowl
Plastic wrap
Smoker or pellet grill
Fruitwood chips or pellets (apple recommended)

Ingredients

Medium russet potatoes
Unsalted butter
All-purpose flour (or gluten-free alternative)
Milk: whole or 2%
Sharp cheddar cheese, plus more for optional topping
Gruyere cheese
Ground mustard powder (sub with yellow mustard)
Onion powder
Ground nutmeg
Salt and black pepper to taste

Preparing your grill and potatoes

Preheat your pellet grill to 350 degrees F, or set up your smoker or grill for indirect cooking. Add wood chips to the smoker five minutes before the au gratin potatoes go on.
Wash, dry, and slice potatoes.
Place them into a microwave-safe dish, cover them with plastic wrap, and microwave for 8 minutes, until slightly tender.
Remove from microwave, take off the plastic wrap, and let the potatoes cool for 10 minutes before handling.

The sauce

Melt butter in a medium-sized saucepan. Add flour and cook over medium-high heat for 1 minute, stirring often.
Next, add onion powder and nutmeg. Slowly whisk in milk, then fold in the mustard and cheese.
Reduce heat to medium, and continue stirring until the cheese has melted and the sauce has thickened. Add salt and pepper to taste.
Layer potatoes in the dish or cast iron skillet. Season lightly with salt and black pepper, and pour cheese sauce evenly over the potatoes.

Cooking Au Gratin Potatoes

Place pan into the smoker, close the lid, and cook for 45-55 minutes.
During the last 15 minutes of cooking, top the potatoes with your desired amount of cheddar cheese.
Once the smoked au gratin potatoes are golden brown and fork tender, remove them from the grill or smoker and let them rest for 10-15 minutes before serving.

Oven method

Prepare sauce and potatoes as directed—bake au gratin potatoes in a casserole dish at 350 degrees for 55 minutes, until tender.

Leftover au gratin potatoes

Store leftover smoked au gratin potatoes in an airtight container in the refrigerator for 3-4 days. Freeze in individual portions and microwave for 3-3 1/2 minutes or until warmed through.

Pairings

This versatile cheesy casserole can be served as the main course or paired with beef roasts, ham, chicken, and more! Here are some of my favorite pairings below.