Plenty of garlic and cheese in this Garlic Parmesan Au Gratin Potatoes recipe with layers of thinly sliced potatoes, Parmesan cheese, and garlic. Serve it as a Thanksgiving or Christmas side dish or alongside meat and potatoes for Sunday supper.
Every Thanksgiving, there’s one conversation that always happens – what kind of potatoes are we making this year? Most of the time it’s mashed, but sometimes it’s scalloped or au gratin.
Confession – I grew up making au gratin potatoes from a box because that’s how my parents made them. Bring milk to a boil, add box contents, cook.
It wasn’t until I bought a handheld mandoline (affiliate link) I started making my own because I can never slice the potatoes thinly (and consistently) enough for an entire dish.
That begs the next question – what’s the difference between scalloped and au gratin? After spending numerous hours researching and reading through recipes, nobody else knows either.
The main difference is au gratin has cheese while scalloped doesn’t, but most recipes, including my easy cheesy stovetop scalloped potatoes, uses cheese.
Another difference is au gratin has breadcrumbs on top, but most au gratin recipes didn’t include breadcrumbs.
I’ve also seen recipes written as au gratin potatoes vs. potatoes au gratin.
In conclusion, the rest of the world doesn’t know the difference between scalloped and au gratin. They DO know anything with cheese and potatoes is a winner, no matter what you call it.
And when there’s garlic and cheese involved, you know it’s going to be a winning side dish with these Garlic Parmesan Au Gratin Potatoes. Layers of thinly sliced potatoes baked with plenty of cheesy goodness.
How do you make au gratin potatoes from scratch?
The key to au gratin is layering thinly sliced potatoes with cheese, garlic, and seasoning. Once layered, pour cream until the potatoes are covered then top with even more cheese.
Using a mandoline ensures each potato is thinly sliced to the same consistency. Otherwise they may unevenly bake in the oven.
How do you make au gratin potatoes in the oven?
This particular recipe is baked in the oven rather than the stovetop. First, you want to use an oven-proof casserole dish. The baking dish in these photos is from the thrift store and says oven safe on the bottom.
It’s a 1 quart baking dish, so it makes roughly 4 servings. You can probably stretch it to 6 servings if you’re serving it for Thanksgiving.
You can also use a 1 1/2 quart casserole dish, but I wouldn’t go much larger than that because the layers may not cook properly.
What’s in au gratin potatoes?
The ingredients for Garlic Parmesan Au Gratin Potatoes are potatoes, cheese, and heavy cream with additional flavors such as garlic and thyme.
It’s important to use heavy cream instead of milk because the fat is important for the cheese sauce to bake properly. Otherwise, the sauce would be too thin and not stick to the potatoes.
If you don’t use heavy cream often, you can buy a small pint so you don’t have any leftover (although leftover heavy cream makes excellent whipped cream for pumpkin pie).
Which potato is best for au gratin?
I personally think Russet potatoes make the best potato for au gratin because of their higher starch level. However, I’ve seen other gratin recipes using Yukon gold or even red potatoes. Whichever potato you choose, bake until the potatoes are fork tender.
Which cheese is best for au gratin
Since au gratin has cheese, let’s talk cheese. There’s no right or wrong answer. Usually when I think of au gratin, I think of cheddar cheese.
However, in this recipe I changed it up and used Parmigiano Reggiano, which is imported exclusively from Italy and made with only three ingredients – milk, salt, and rennet. Sometimes you’ll see domestic Parmesan made in the U.S., which usually contains additives.
You can easily recognize it from the pinholes in the rind that spell out Parmigiano Reggiano, but depending on how the cheese wheel is cut, the holes may not always be present. Ask your local cheese person if you’re unsure about whether the cheese is imported.
Other Thanksgiving Side Dish Recipes
- 1 tablespoon unsalted butter, softened
- 1 1/2 pounds russet potatoes (roughly 4 large potatoes), peeled and thinly sliced (preferably with a mandoline for even, thin cuts)
- 1/2 cup chopped onion
- 2 garlic cloves, minced
- 1 1/4 cups shredded Parmigiano Reggiano
- 1 teaspoon fresh thyme
- 1/2 teaspoon salt
- 1/4 teaspoon pepper
- 1 cup heavy whipping cream
- Preheat oven to 350F. Rub the butter in the bottom and up the sides of a 1-quart casserole dish.
- Layer some of the sliced potatoes in a single layer in the bottom of the dish, slightly overlapping.
- In a large bowl, mix together the onion, garlic, 1 cup Parmigiano Reggiano, thyme, salt, and pepper. Sprinkle about 1/3 of the mixture over the potato layer.
- Repeat the layering two more times, ending with a layer of potatoes.
- Pour the cream over the potatoes, filling in between the spaces. Top with remaining 1/4 cup Parmigiano Reggiano.
- Bake 60-90 minutes or until the top is golden brown and the potatoes are soft.