Caramelized Onion Scalloped Potatoes

These Caramelized Onion Scalloped Potatoes are beyond indulgent and the perfect addition to your holiday dinner or anytime you’re hosting a nice dinner! They are insanely creamy, herby, and sure to be enjoyed by all who are around your table.

I do think the photos speak for themselves, but just to give you an idea of the deliciousness of these scalloped potatoes, I start with caramelizing the onions — I promise it’s worth the time — the create a delicious sauce with garlic, white wine, heavy cream and butter…YUM.

The potatoes are layered with this sauce and gruyere cheese resulting in bubbly, deliciousness. Pair these Caramelized Onion Scalloped Potatoes with my Herb-Crusted Beef Tenderloin and you’re on your way to a delicious meal that is sure to impress. 

Ingredients:

• Olive Oil
• Yellow Onions
• Salt
• Russet Potatoes
• Garlic
• Unsalted Butter
• White Wine
• Heavy Whipping Cream
• Fresh Thyme Leaves
• White Pepper
• Garlic Powder
• Cayenne Pepper
• Gruyere Cheese

If you are looking for a dairy-free scalloped potato recipe, try my Whole30 Scalloped Potatoes!

Step-by-Step:

step one: caramelize the onions

To start this recipe, caramelize the onions in a large skillet. This takes about 30 minutes, but I promise it is worth it! Allowing the onions to slowly cook in oil and salt brings so much flavor to the sauce you will make for the potatoes.

Step two: prep the potatoes

While the onions are caramelizing, thinly slice the potatoes. Once thinly sliced, add to a large bowl and fill the bowl with water. This prevents the potatoes from browning!

Step Three: make the sauce

Once the onions are caramelized, drain off any excess oil if needed. Next, add the garlic and butter to the skillet with the onions. After the garlic has sauteed for a minute, add the white wine and cook until it has reduced by half. Next, stir in the heavy cream, thyme, and other seasonings. Stir to combine then simmer until the sauce begins to thicken. Once thickened, remove from heat while you begin layering the potatoes.

step 4: assemble the scalloped potatoes

Once the sauce is ready, assemble the scalloped potatoes. Start the layering by adding ½ of the potatoes to the bottom of the greased baking dish. Top this layer with 1/3 of the sauce then add 1/4 cup of cheese. Repeat with a layer of the remaining potatoes, followed by the remaining sauce. Do not add an additional cheese layer yet! Cover with foil and bake until potatoes are tender, about 40 minutes.

Step five: Finish the potatoes

Once the potatoes are tender, carefully remove them from the oven. Carefully remove the foil then top with the remaining cheese. Increase the heat to 425℉ then place the potatoes back into the oven and bake until the cheese is bubbly and lightly browned. Let cool slightly then serve!

Recipe FAQs:

I hope you enjoy these Caramelized Onion Scalloped Potatoes as much as my family and friends do!

5 from 21 votes

Caramelized Onion Scalloped Potatoes

Prep: 50 minutes mins

Cook: 50 minutes mins

Total: 1 hour hr 40 minutes mins

Servings: 8 People

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Ingredients 

1x2x3x

• ▢ ¼ cup olive oil
• ▢ 2 medium yellow onions halved and thinly sliced
• ▢ 2 tsp Kosher salt
• ▢ 3 lb russet potatoes
• ▢ 2 cloves garlic minced
• ▢ 2 tbsp unsalted butter
• ▢ ½ cup white wine
• ▢ 1 pint heavy whipping cream about 2 cups
• ▢ 1 tbsp finely chopped thyme leaves
• ▢ ½ tsp white pepper
• ▢ ½ tsp garlic powder
• ▢ ¼ tsp cayenne pepper optional
• ▢ 3/4 cup shredded gruyere cheese

Instructions 

• In a large skillet over medium heat, add the olive oil, onions and 1 tsp of salt. Stir to combine. Let the onions caramelize for 35-40 minutes, stirring often so that they brown but being careful not to burn.
• While the onions are caramelizing, peel your potatoes and slice them into 1/4-inch rounds. I prefer to use a mandolin to ensure they are a uniform ¼ inch thickness, but if you do not have one, you can cut them carefully with a sharp knife in as even slices as you can get!
• Add the sliced potatoes to a large bowl and fill with water until they are just covered, set aside (this helps prevent them from browning while you finish your onions).
• Preheat your oven to 375℉ and grease a 9×13 baking dish.
• Once the onions are caramelized, drain off any excess oil then place back over medium heat.
• While the oven preheats, add the garlic and butter to the skillet with the onions. Melt the butter and sauté the garlic for about a minute.
• Add the white wine to the skillet and let it cook until it has reduced by half, about 2 minutes. Once reduced, add the heavy cream and whisk to combine and bring to a simmer. Stir in the thyme, white pepper, garlic powder, cayenne (if using) and the remaining 1 tsp of salt. Stir to combine and cook, simmering and stirring often, to allow the flavors to mend and the sauce to slightly thicken, 4 more minutes. Remove from heat and set aside while you begin to layer your potatoes.
• Drain the potatoes then add ½ of the potatoes to the bottom of the greased 9 x 13 pan in an even layer. Pour ⅓ of the sauce over the first layer of the potatoes (about 1 cup) then add ¼ cup of the cheese. Next, add the remaining potatoes then pour the remaining sauce over (do not add the remaining cheese yet!)
• Cover with foil and transfer to the preheated oven and bake until the potatoes are just fork-tender, about 40 minutes.
• Once tender, carefully remove the potatoes from the oven and increase your heat to 425℉.
• Remove the foil and top the potatoes with the remaining ½ cup of cheese. Place back into the oven and cook, uncovered, for 8 to 10 minutes, or until the cheese is bubbly and lightly browned over the top.
• Let cool for 5 to 10 minutes before serving! Enjoy!

Notes

Serving Note: This will actually serve 8-10 people!

If making this alongside my Herb-Crusted Beef Tenderloin: Cook the potatoes at 375℉ then remove from the oven and set aside (covered) while your tenderloin is cooking at 425℉. Then, after you pull the tenderloin out of the oven and let it rest, add the potatoes into the oven uncovered to get your cheese bubbly.

Make ahead note: These really don’t do that well to prep ahead, as without baking, the potatoes get pretty browned/funky. It’s best made same day OR you can make it fully (potatoes are baked and all), let it cool completely, cover and refrigerate. Then, the day of serving you just need to reheat it in the oven at 350℉ or 375℉, covered, until nice and hot. But, you can caramelize the onions ahead of time! Make the day ahead then store, covered, in the fridge.

Nutrition information is automatically calculated, so should only be used as an approximation.

Additional Info

Author: Alex Snodgrass

Servings: 8 People

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