Sometimes the old school Potato Gratin recipe needs a bomb upgrade. I kept it creamy like usual and used my fave Yukon Golds for the base. But I added a secret ingredient…… butternut squash, which is just next level y’all. It adds just a little sweetness to the savory. That, along with a little soy sauce, honey and cheese takes this to another level. I swear you will be scraping your dish clean.
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How to make a Potato Gratin
Step 1: Wash and peel the potatoes, reserving the peels. Set aside.
Step 2: Wash the squash. Remove and discard 1 inch off the top and the bottom. Using a vegetable peeler, peel the squash until you reach the deep-orange flesh. Remove and discard the seeds, but reserve the peels. Set aside.
Step 3: Slice the potatoes and squash paper thin using a mandoline slicer. Fill a large bowl with cold water and transfer the slices.
Step 4: Heat the cream, honey, soy sauce, and reserved squash and potato peels in a large pot over medium heat. Cook until the liquid has reduced by ⅓, about 30 minutes. Add the butter.
Step 5: Pour the mixture into a blender and blend until smooth.
Step 6: Place the egg yolks in a bowl large enough to hold the cream mixture. Whisk the yolks continuously while slowly pouring the warm liquid into the bowl. Keep whisking until all the liquid is fully incorporated. The goal is to temper, not cook, the eggs.
Step 7: Place the squash in a single layer in the prepared baking dish. Place the potatoes on top of the squash. Keep assembling the gratin in alternating layers (potato, then squash, then potato, and so on) slightly overlapping each layer.
Step 8: Add just enough of the cream mixture to cover the vegetables. Repeat this process until all of the vegetables are used.
Step 9: Cover the baking dish with aluminum foil and bake for about 45 minutes to 1 hour. Remove from the oven, remove the foil, and top with the parmesan cheese.
Step 10: Change the oven setting to broil, and cook under the broiler for another 5 to 7 minutes, until the cheese is browned on top.
Potato Gratin Recipe
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Equipment
- 8×8 square baking pan
- peeler
Ingredients
- 2 tablespoons unsalted butter plus more for greasing
- 3 Yukon gold potatoes
- ½ butternut squash
- 1½ cups heavy cream
- 3 tablespoons honey
- 3 tablespoons soy sauce
- 3 large egg yolks
- ½ cup parmesan cheese grated
Instructions
- Preheat the oven to 350ºF. Grease the inside of an 8 × 8-inch baking dish with butter.
- Wash and peel the potatoes, reserving the peels. Set aside.
- Wash the squash. Remove and discard 1 inch off the top and the bottom. Using a vegetable peeler, and working away from yourself, peel the squash until you reach the deep-orange flesh. Remove and discard the seeds, but reserve the peels. Set aside.
- Fill a large bowl with cold water and set nearby. Using a mandoline slicer, slice the potatoes and squash paper thin, then transfer the slices to the bowl of water.
- In a large pot, heat the cream, honey, soy sauce, and reserved squash and potato peels over medium heat and cook until the liquid has reduced by ⅓, about 30 minutes. Add the butter. Pour the mixture into a blender and blend until smooth.
- In a bowl large enough to hold the cream mixture, place the egg yolks. Whisk the yolks continuously while slowly pouring the warm liquid into the bowl. The goal is to temper, not cook, the eggs.
- In the prepared baking dish, place the potatoes and squash in alternating layers (potato, then squash, then potato, and so on), slightly overlapping each layer. Once a layer is finished, add just enough of the cream mixture to cover the vegetables. Repeat this process until all of the vegetables are used. Place the baking dish on top of a baking sheet to catch drips. Cover the baking dish with aluminum foil and bake for about 45 minutes to 1 hour. Remove from the oven, remove the foil, and top with the parmesan cheese. Change the oven setting to broil. Cook under the broiler for another 5 to 7 minutes, until the cheese is browned on top.
- Remove from the oven. Let the gratin rest for about 15 minutes before serving.
Notes
To Store
It will keep in the fridge for about 3 days. Just make sure you bring it to room temp completely before wrapping or transferring to an airtight container and adding to the fridge. To reheat, just cover with foil and add to a 350 oven for about 10 minutes and then remove the foil to get the top crispy again. You can also freeze for up to 2 months.Nutrition
Recipe Tips
- Pat Them Dry: After slicing the potatoes and squash, pat them dry with a towel before layering. Excess moisture can mess with the texture and make it watery.
- Layer Like a Pro: Take your time with those layers, boos! Overlap the potato and squash slices slightly so they stay stacked and don’t slip apart when you slice into it.
- Let That Sauce Simmer: Don’t rush the sauce! Let it reduce and thicken for the full 30 minutes. That’s how you’ll get a deep, rich flavor.
- Broil with Caution: When you switch to broil, keep an eye on it. That cheese can go from golden and bubbly to burnt REAL quick.
Ingredient Notes
- Potatoes: If you don’t have Yukon golds, you can easily swap them for russets or even red potatoes.
- Butternut Squash: Try using acorn squash or sweet potatoes instead. Acorn squash has a slightly nuttier flavor, and sweet potatoes will bring in a little extra sweetness.
- Heavy Cream: Use half-and-half or whole milk. Just know it won’t be quite as rich, but still creamy.
- Cheese: Pecorino romano or even a sharp cheddar will bring some new flavors to the potato and squash gratin.
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I'll email this recipe to you, so you can come back to it later!
Recipe Help
Yup! You can prep the entire dish, cover it, and store it in the fridge for up to a day before baking. When you’re ready to serve, just pop it in the oven as usual.
It’s not a must, but it makes your life sooo much easier. If you don’t have one, a sharp knife and some patience will get the job done!
You can still get a golden top by cranking up the oven to 425°F for the last 5-10 minutes of baking.
More Potato Recipes
- Smashed Potatoes
- Twice Baked Potatoes
- Scalloped Potatoes
- Roasted Fingerling Potatoes
- Southern Smothered Potatoes
- Potato Rolls
Reprinted with permission from New Prairie Kitchen by Summer Miller, Agate Midway, 2015.
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Hi Jocelyn,
I am a new subscriber and made this dish last night. My husband doesn’t like squash, so i didn’t tell him what was in the dish, he thought it was potatoes :). He almost eat the whole dish. Thanks. Soooo good.