Last Updated on November 4, 2021 by Kathryn Donangelo
This is the BEST Potato Gratin Recipe! Made with thinly sliced Yukon Gold potatoes that are layered in a silky smooth cheese sauce then baked until lightly golden brown. This is the perfect side dish for any occasion!
Potato Gratin is one of my favorite side dishes! This homemade recipe is so simple to make but produces a such decadent satisfying dish. Loaded with thinly sliced tender Yukon Gold potatoes that are smothered in a velvety garlic-thyme cheese sauce. The potatoes are then topped with more shredded cheddar, Jack cheese, and gruyere and baked until lightly golden brown on top. This is truly the BEST Potato Gratin recipe!
This easy and delicious recipe is a wonderful side dish for Thanksgiving, Christmas, and even Easter!
- Yukon Gold Potatoes
- Yellow onions
- All-purpose flour
- Whole milk or cream
- Shredded sharp cheddar, gruyere, and Monterey Jack
- Black pepper
- Fresh thyme
- Low-sodium chicken broth
Yukon Gold Potatoes: I love the buttery flavor of Yukon Golds and feel their rich flavor adds to the overall decadency of this dish, however; feel free to use Russet or Red potatoes if you prefer.
Gruyere: While this recipe calls for gruyere, feel free to use any Swiss type of cheese such as Emmental, Jarlsberg, or Raclette.
Fresh thyme: You can substitute dry if you cannot find fresh.
Low-sodium chicken broth: If you are unable to find low-sodium broth, feel free to use regular. Just be sure to cut down the added salt to a 1/4 teaspoon otherwise your dish will become too salty.
HOW TO MAKE POTATO GRATIN
STEP ONE: Preheat oven to 400 degrees. Spray 9×9 baking dish with nonstick cooking spray or grease with butter or oil. Set aside. Slice potatoes into 1/8 inch rounds. Set aside until ready to assemble.
STEP TWO: To make the cheese sauce, melt butter and cook onions in a medium saucepan. Next whisk in flour until thickened. Slowly whisk milk, cheeses, salt, pepper, garlic, and thyme. Once all ingredients are added, vigorously whisk until smooth. Whisk in chicken broth and cook until sauce begins to simmer. Remove from heat.
STEP THREE: Layer 1/3 of the potatoes into the prepared dish. Pour 1/3 of the sauce on top of the potatoes. Repeat 2 more times.
STEP FOUR: Cover with aluminum foil and bake for 40 minutes. Remove foil and sprinkle with remaining 1 cup of cheddar, Jack, and gruyere. Reduce oven temperature to 350 degrees F. Return uncovered dish to oven and bake for another 40 minutes or until potatoes are tender and top is lightly golden brown. Serve immediately and enjoy!
- Swap out gruyere with aged white cheddar for a bold and tangy flavor
- Add mace or nutmeg to add a hint of warmth
- Add leftover cubed ham for a potato gratin with ham dish
- If you’d like to lighten up the dish, use reduced fat or fat free cream or even half-and-half. Just be aware that dish won’t be as rich.
HOW TO STORE
Store any leftovers in an airtight container in the fridge for up to 4 days.
When ready to eat, reheat covered leftovers in the oven at 350 degrees until warmed through.
CAN POTATO GRATIN BE MADE AHEAD OF TIME?
This is a perfect make ahead dish! Prepare dish according to recipe, cover, and place in refrigerator for up to 2 days in advance and bake the day of.
You can also par bake a covered dish for 30 or 40 minutes and finish cooking the day of in a 375 degree oven for 30-40 minutes uncovered or until golden brown and tender.
CAN POTATO GRATIN BE FROZEN?
Sure can! Wrap the casserole with aluminum foil and place in the freezer for up to a month. Thaw in the refrigerator overnight and when ready to bake; bake in a 350 degree oven until warmed through.
MORE SIDE DISH RECIPES TO TRY:
- Herb-Roasted Sweet Potatoes
- Sweet and Moist Cornbread
- Slow Cooker Mashed Potatoes
- Roasted Garlic Parmesan Brussel Sprouts
- Fluffy Dinner Rolls
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The Best Potato Gratin Recipe
- 2.5 lbs. Yukon Gold Potatoes; peeled and thinly sliced I highly recommend using a mandolin
- 2 Tbsp. butter
- 1/2 cup yellow onions; chopped
- 2 Tbsp. all-purpose flour
- 2 cups whole milk or cream
- 1 cup sharp cheddar cheese; shredded
- 1 cup gruyere cheese; shredded
- 1/2 cup Monterey Jack cheese; shredded
- 1/2 tsp. salt
- 1/2 tsp. black pepper
- 2 cloves garlic; minced
- 1 tsp. fresh or dried thyme
- 1/2 cup low-sodium chicken broth
- Preheat the oven to 400 degrees F. Spray a 9x9 inch square baking dish (you could also use an 8x12 or 9x13 inch dish) with nonstick cooking spray or grease with butter or oil.
Make the cheese sauce
- In a medium saucepan on medium heat, cook butter and onions until butter has meted. Whisk in flour. Once it has thickened, add milk, cheeses, salt, pepper, garlic and thyme. Vigorously whisk for a few minutes making sure there isn't any lumps. Add in chicken broth and whisk again. Bring cheese sauce to a simmer for a few minuets. It should be creamy and the consistency should resemble a gravy.
Assemble Potato Gratin
- Add 1/3 of the sliced potatoes in the baking dish. You can layer the potatoes in rows or scatter them. Pour 1/3 of the cheese sauce mixture evenly over the potatoes and repeat with the next 2 layers.
- Cover the baking dish with foil and bake for 40 minutes.
- Remove the foil and sprinkle more cheese (about 1 cup of total of cheddar, Jack and gruyere). Reduce the oven temperature to 350 degrees F. Return the baking dish to the oven and bake for another 40 minutes. The potatoes will be lightly golden brown when done and you will be soft. Let cool for a few minutes and enjoy!
- Use a mandolin slicer to cut the potatoes extra thin. I like to slice my potatoes to 1/8 of an inch in thickness and a mandolin does this quickly and efficiently.
- To speed up the baking process, microwave the sliced potatoes for 5-10 minutes to slightly soften prior to assembly. You can also boil the sliced potatoes for approximately 5 minutes or until soft and drain.
- To speed up the prep of this dish, slice the potatoes ahead of time. Keep sliced potatoes in a bowl full of ice-cold water in the fridge and pat dry when ready to use. Will keep for up to 24 hours ahead of time.
- For best results, always grate your own cheese. Store bought pre-shredded cheeses have an anti-caking agent added which prevents cheese from melting as well as it should.