Name: Cheesy Potatoes Au Gratin
Prep time: 20 min
Cook time: 1 h
Total time: 1 h 20 min
Cuisine: American
Ingredients: 2 1/2 pounds russet potatoes, peeled and thinly sliced; 6 slices thick-cut bacon, chopped; 3 tablespoons unsalted butter; 1 small yellow onion, finely diced; 3 cloves garlic, minced; 3 tablespoons all-purpose flour; 2 cups whole milk; 1 cup heavy cream; 1 teaspoon kosher salt; 1/2 teaspoon black pepper; 1/2 teaspoon smoked paprika; 1/2 teaspoon dried thyme; 1 1/2 cups shredded sharp cheddar cheese, divided; 1/2 cup shredded Gruyère cheese; 1/4 cup grated Parmesan cheese; 2 tablespoons chopped fresh parsley

Golden, bubbling, and impossibly creamy, these Cheesy Potatoes Au Gratin are the kind of side dish that steals the whole meal. Thinly sliced potatoes are baked in a velvety garlic cream sauce, then smothered in a blanket of melted cheddar, Gruyère, and crispy bacon.

Whether you’re planning a holiday feast, a cozy Sunday dinner, or just need a crowd-pleasing side for a weeknight roast, this pan of cheesy comfort fits right in. The potatoes bake up tender and rich, with just enough crispy edges to keep every bite interesting.

What Kind of Potatoes Work Best for Cheesy Potatoes Au Gratin?

For the creamiest, most luxurious texture, starchy potatoes like russets are your best friend. They soften beautifully in the oven and release just enough starch to naturally thicken the sauce, so every slice is cloaked in cheesy goodness. Waxy potatoes like Yukon Golds also work well if you prefer slices that hold their shape a bit more.

Whatever potato you choose, the secret is in the slicing: go thin and even. Using a mandoline or food processor keeps the layers uniform so they cook at the same pace and soak up the sauce evenly from corner to corner.

Ingredients for Cheesy Potatoes Au Gratin

Russet potatoes These create ultra-tender layers and help naturally thicken the cheesy cream sauce as they bake.

Thick-cut bacon Adds smoky, salty crunch on top and a rich, savory flavor that runs through the whole dish.

Unsalted butter Forms the base of the roux for the sauce, adding buttery richness without making the dish too salty.

Yellow onion Brings sweetness and depth, balancing all the cheese and cream.

Garlic Perfumes the sauce with warm, savory flavor so the potatoes never taste flat.

All-purpose flour Helps the sauce thicken into a silky blanket that clings to every potato slice.

Whole milk Lightens the cream while still keeping the sauce velvety and smooth.

Heavy cream Delivers that over-the-top luscious texture you expect from classic au gratin.

Sharp cheddar cheese Melts into a bold, tangy layer of gooey cheese that defines this dish.

Gruyère cheese Adds nutty, slightly sweet flavor and gorgeous melt, taking the potatoes from simple to restaurant-worthy.

Parmesan cheese Sprinkled on top for a salty, golden-brown crust that crisps as it bakes.

Smoked paprika Infuses a gentle smoky warmth and enhances the golden color of the cheese.

Dried thyme Adds an herby note that pairs perfectly with potatoes, cream, and cheese.

Kosher salt and black pepper Essential for balancing the richness and bringing out every flavor in the pan.

Fresh parsley A bright, fresh finishing touch that makes the cheesy layers pop visually and in flavor.

How To Make the Cheesy Potatoes Au Gratin

Step 1: Prep the Pan and Potatoes

Preheat your oven to 375°F (190°C). Grease a 9×13-inch baking dish with butter or nonstick spray. Peel the potatoes and slice them into thin rounds, about 1/8-inch thick, using a sharp knife or mandoline. Keep the slices in a bowl of cold water while you prepare the sauce to prevent browning.

Step 2: Cook the Bacon

In a large skillet over medium heat, cook the chopped bacon until crispy and browned. Transfer the bacon pieces to a paper towel–lined plate, leaving about 2 tablespoons of bacon drippings in the pan. This flavorful fat will help season the sauce.

Step 3: Build the Flavor Base

Add the butter to the skillet with the bacon drippings. Once melted, stir in the diced onion and cook for 3–4 minutes until soft and translucent. Add the minced garlic and cook for 30 seconds until fragrant, stirring constantly so it doesn’t burn.

Step 4: Make the Creamy Cheese Sauce

Sprinkle the flour over the onion mixture and cook, stirring, for 1 minute to form a roux. Slowly whisk in the milk and heavy cream, breaking up any lumps. Season with salt, pepper, smoked paprika, and dried thyme. Simmer for 3–5 minutes until slightly thickened, stirring often. Remove from heat and stir in about 1 cup of the cheddar and all of the Gruyère until smooth and melted.

Step 5: Layer the Potatoes

Drain and pat the potato slices dry. Arrange half of them in an even layer in the prepared baking dish, overlapping slightly. Pour half of the warm cheese sauce over the potatoes, letting it seep between the slices. Repeat with the remaining potatoes and sauce, smoothing the top so everything is covered.

Step 6: Add the Topping

Sprinkle the remaining cheddar and the Parmesan evenly over the top. Scatter most of the crispy bacon over the cheese, reserving a little for garnish after baking.

Step 7: Bake Until Golden and Bubbly

Cover the dish loosely with foil and bake for 35 minutes. Remove the foil and continue baking for 20–25 minutes more, or until the potatoes are tender when pierced with a knife and the top is deeply golden and bubbling around the edges.

Step 8: Rest and Finish

Allow the Cheesy Potatoes Au Gratin to rest for at least 10 minutes before serving so the layers can set. Top with the remaining bacon and a shower of chopped fresh parsley just before slicing into squares and serving.

Serving and Storing Cheesy Potatoes Au Gratin

These potatoes are at their absolute best when served warm, about 10–20 minutes after coming out of the oven. That short rest lets the creamy sauce thicken slightly, so each scoop holds its shape but still feels luxuriously soft and melty.

If you’re serving a crowd, you can bake the dish a few hours ahead, let it cool slightly, then reheat it covered in a 325°F (165°C) oven until warmed through. Leftovers keep well in an airtight container in the refrigerator for up to 4 days. Reheat individual portions in the microwave or in a covered baking dish in the oven with a splash of milk or cream to revive the sauce.

For freezing, assemble the potatoes and sauce in the baking dish but stop before baking. Wrap tightly in plastic wrap and foil, then freeze for up to 2 months. Thaw overnight in the refrigerator and bake as directed, adding an extra 10–15 minutes if needed.

What to Serve With Cheesy Potatoes Au Gratin?

Herb-Roasted Chicken

The juicy, savory flavors of roast chicken pair perfectly with the rich, cheesy potatoes for an effortless comfort-food dinner.

Grilled Steak or Pork Chops

A simple grilled steak or pork chop balances the creaminess of the potatoes with smoky char and protein.

Baked Salmon

Flaky, lemony baked salmon adds a lighter protein option that still feels special alongside such a decadent side.

Holiday Ham

Salty, glazed ham and creamy potatoes are a classic match for Easter, Christmas, or any celebratory meal.

Green Vegetable Medley

Serve with steamed or roasted green beans, broccoli, or asparagus to add freshness and color to the plate.

Crisp Garden Salad

A crisp salad with tangy vinaigrette helps cut through the richness and keeps the meal feeling balanced.

Buttery Dinner Rolls

Use soft rolls to scoop up every last bit of cheesy sauce from your plate.

Want More Cozy Potato Side Dish Ideas?

If these Cheesy Potatoes Au Gratin have you craving even more comforting sides, try a few of these favorites from ChefAlchemy:

Scalloped Potatoes Ultra-creamy, classic layers of potatoes in a silky sauce—perfect for any holiday table. (https://chefalchemy.com/scalloped-potatoes/)
Roasted Parmesan Potatoes and Broccoli A crispy, oven-roasted combo that brings together cheesy potatoes and tender broccoli in one pan. (https://chefalchemy.com/roasted-parmesan-potatoes-and-broccoli/)
Oven Fried Potatoes and Onions Rustic, golden potatoes with caramelized onions for a simple but unforgettable side. (https://chefalchemy.com/oven-fried-potatoes-onions/)
Roasted Potatoes with Baked Feta and Garlic Tangy feta and garlicky roast potatoes that feel fancy but are secretly easy. (https://chefalchemy.com/roasted-potatoes-with-baked-feta-and-garlic/)
Roasted Broccoli and Sweet Potatoes A colorful, sheet-pan side that adds natural sweetness and extra veggies to your plate. (https://chefalchemy.com/roasted-broccoli-and-sweet-potatoes/)

Mix and match them with your favorite mains to build a full menu of cozy, satisfying dinner ideas.

Save This Pin For Later

📌 Save these Cheesy Potatoes Au Gratin to your Pinterest dinner or holiday board so you can find them again whenever a craving for creamy, cheesy comfort hits.

When you make them, I’d love to hear how yours turned out. Did you stick with bacon, or swap in ham or sausage? Did you play with different cheeses or herbs?

Share your tweaks and questions in the comments so we can all keep leveling up our favorite comfort-food side dishes together.

Explore more crave-worthy everyday dinners and indulgent side dish food ideas on ChefAlchemy’s recipe collection over on Pinterest: https://www.pinterest.com/chefalchemy/