These Hasselback au Gratin Potatoes are stellar! From the crispy cheesy top to the creamy garlicky deliciousness underneath. People will RAVE!
Note: although garlic is oftten a preferred ingredient in the case of these potatoes, the garlic powder infuses all the cream with flavor.
Adjust oven rack to middle and preheat to 400 degrees F. Grease a 2-quart casserole dish (I use an 11 x 7″) with butter or spray.
Add half the Parmesan and/or Asiago or mix of both to a large bowl. Mix in cream, minced garlic or garlic powder & salt and pepper. Add potato slices and toss to coat, separating slices so each potato is covered. Working by the handful, pick up potatoes, trying to keep a little cheese between the slices and pat into a fairly even horizontal stack. You’re looking to keep the side edges of the potato pretty even but have a lot of variation in the stack on the top edge, so turn some around as needed..
Working in rows along the outside edges, place in casserole with the top edges up and aligned vertically. Continue placing potatoes in casserole, working around the perimeter and into the center until all potatoes have been added and potatoes are pretty tightly packed. You’ll want them tight enough so that you can’t get a finger width in, but not so tight that there’s not room for the cream to seep through. If necessary, slice additional potato, coat with cream mixture, and add to casserole. Pour excess cream/cheese mixture evenly over potatoes until the mixture comes half to 2/3rds of the way up the sides of the casserole. You may not use all the cream or you may need to add a bit more. Mix the reserved Parmesan/Asiago with the cheddar cheese and set aside.
Choose method of baking but do place a large sheet of foil on the oven rack under the baking dish to catch any potential spill over:
Method 1, the original Serious Eats Method:
Cover tightly with foil and transfer to oven. Bake for 30 minutes. Remove foil and continue baking until top is pale golden brown, about 30 minutes longer. Carefully remove from oven, sprinkle with reserved cheese, and return to oven. Bake until the potatoes test done with tested with a knife (it should slide in easily with little resistance) and the top is deep golden brown and crisp, about 30 minutes longer. Remove from oven, let rest for a few minutes, and serve.
Method 2, my highly recommended “rogue” part microwave method:
Cover with a layer of plastic wrap and microwave on high for 30 minutes. Make sure to preheat oven at appropriate time so it’s at 400 degrees F. when the microwave time is over. Remove from microwave, sprinkle with cheese and bake for 30 minutes until the potatoes test done with a knife (it should slide in easily with little resistance) and the potatoes are crisp & cheese is melted and the cheese is deep golden brown. Remove from oven, let rest for a few minutes, and serve.
Note: there is always going to be a bit of variable in this dish – depending on the shape of the dish & the size of the potatoes you may need more or less to fill the dish. That can affect just how much cream you’ll need, too. I try to eyeball the potatoes next to the dish to estimate how many I’ll need but be prepared & have an extra potato on hand if you need to fill in.
Although this recipe should serve six to eight, these were so good four of us polished this off. Judge accordingly.
Keywords: au gratin, au gratin potatoes, cheddar, Cheese, Cream, hearty sides, J. Kenji López-Alt, Potatoes, serious eats, Side, Parmesan, Asiago Cheese