Creamy Two-Potato Gratin with Gruyere

Equipment

• Oven
• Saucepan

Ingredients

• ¼ cup butter, divided
• 2 shallots, diced
• 2 cups heavy whipping cream
• 2 Tbsp. chopped fresh parsley
• 1 Tbsp. chopped fresh chives
• 1 tsp. kosher salt
• ½ tsp. ground white pepper
• ⅛ tsp. freshly grated nutmeg
• 1½ lb. Yukon gold potatoes
• 1½ lb. sweet potatoes
• 2 cups milk
• 6 oz. Gruyère cheese, shredded (about 1½ cups)
• 1 oz. Parmesan cheese, grated (about ¼ cup)

Instructions

1. 1Preheat the oven to 375°F. Melt 3 tablespoons of butter in a saucepan over medium heat and cook the diced shallots for 2 minutes.
2. 2Stir in the heavy cream, parsley, chives, salt, white pepper, and nutmeg. Simmer the mixture for 2 minutes, then remove the pan from the heat and let it cool for 15 minutes.
3. 3Peel and thinly slice the Yukon gold and sweet potatoes. Place all the slices into a large microwave-safe bowl and pour the milk over them.
4. 4Cover the bowl tightly with plastic wrap and microwave on high for 5 minutes. Carefully uncover the bowl to gently stir the potatoes, then cover again and microwave for another 5 minutes. Drain the potatoes well and discard the leftover milk. This par-cooking step ensures the potatoes bake evenly in the oven.
5. 5Coat the inside of a 13-by-9-inch baking dish with softened butter.
6. 6Arrange one-third of the drained potatoes in the bottom of the prepared dish. Pour one-third of the cooled cream mixture over the potatoes and sprinkle with 1/2 cup of the shredded Gruyere cheese. Repeat this layering process two more times, finishing with an even layer of grated Parmesan cheese on top.
7. 7Cut the remaining 1 tablespoon of butter into small pieces and scatter them across the top of the gratin. Cover the baking dish tightly with aluminum foil.
8. 8Bake the covered gratin for 30 minutes. Remove the foil and continue baking for about 20 more minutes until the top is golden brown and bubbling. Let the dish rest for 10 minutes so the sauce can thicken before slicing.

Recipe Details