Dauphinoise Potatoes

Ingredients

• 8 oz. Gruyère, coarsely grated (about 2 cups), divided, rind reserved if attached
• 1 (12-oz.) can evaporated milk
• 2 cups heavy cream
• 2 garlic cloves, finely grated
• 1 dried bay leaf
• 1 sprig rosemary
• 1 sprig thyme
• 2 Tbsp. Dijon mustard
• 1 Tbsp. Diamond Crystal or 1¾ tsp. Morton kosher salt
• 1 tsp. freshly ground pepper
• ¼ tsp. freshly grated nutmeg
• 2½ lb. Yukon Gold potatoes (about 7 small)

Steps

1. Place a rack in middle of oven and preheat to 375°. Combine Gruyère rind (if using), one 12-oz. can evaporated milk, 2 cups heavy cream, 2 garlic cloves, finely grated, 1 dried bay leaf, 1 rosemary sprig, 1 thyme sprig, 2 Tbsp. Dijon mustard, 1 Tbsp. Diamond Crystal or 1¾ tsp. Morton kosher salt, 1 tsp. freshly ground pepper, and ¼ tsp. freshly grated nutmeg in a medium Dutch oven or other heavy pot.
2. Peel 2½ lb. Yukon Gold potatoes (about 7 small), then slice into ⅛"-thick rounds with a mandoline or knife, adding directly to cream mixture as you go to prevent oxidation.
3. Place pot over medium heat and bring liquid to a gentle simmer. Immediately reduce heat to medium-low and cook at a bare simmer (do not let it boil), stirring often to help potatoes cook evenly, just until potatoes are fork-tender (you don’t want them to be fully cooked), 6–8 minutes. Remove from heat; fish out herbs and cheese rind and discard.
4. Layer half of the potatoes evenly into an 8×8" glass or ceramic baking dish. Spread ¾ cup cream mixture over, then top evenly with 5 oz. Gruyère, coarsely grated (about 1⅓ cups). Arrange remaining potatoes in an even layer on top and pour another ¾ cup cream mixture over. (You might have some cream mixture leftover in the pot.) Sprinkle remaining 3 oz. Gruyère, coarsely grated (about ⅔ cup) on top.
5. Place baking dish on a rimmed baking sheet and bake until edges are bubbling, top is golden brown, and potatoes are tender, about 45 minutes. Transfer baking dish to a wire rack and let potatoes cool 15 minutes before serving. (If oil has pooled on top, blot away with a paper towel.)