Gratin de pommes de terre normand

• 2 pounds (900 g) boiling potatoes, peeled
• 3 cups (¾

Cut the potatoes into ⅛-inch (⅓ cm) thick slices. Cover them with the milk in a large saucepan and add the nutmeg, tarragon, and seasonings. Bring to a simmer and cook for 4 minutes. Meanwhile, butter the baking dish. Using a slotted spoon, remove the potatoes from the pan and arrange them in an even layer in the buttered dish. Taste the milk carefully for seasoning and pour it over the potatoe