Classic Gratin Dauphinois

From the garden

• 2½ lb main-crop potatoes, peeled and sliced 1/8 inch thick · starchy varieties like Yukon Gold or russet
• 2 cloves garlic, one halved, one minced

From the pantry

• 1½ cups whole milk
• 1½ cups heavy cream
• 1 tbsp butter, softened · for the dish
• ¼ tsp ground nutmeg · freshly grated if you have a whole nut
• 1 bay leaf (optional)
• salt · to taste
• black pepper

1. Heat the oven to 325°F. Rub a 2-quart baking dish all over with the cut face of the halved garlic clove, then butter it generously, sides included.
2. Peel the potatoes and slice them 1/8 inch thick, on a mandoline if you have one, and keep the slices dry. Do not rinse them: the surface starch is what thickens the cream and binds the layers.
3. Combine the milk, cream, minced garlic, nutmeg, bay leaf, a teaspoon of salt, and several grinds of pepper in a wide pan. Slide in the potato slices, bring to a bare simmer, and cook 8–10 minutes, stirring gently once or twice, until the liquid has thickened and a slice bends without snapping.
4. Fish out the bay leaf and tip everything into the dish, spreading the slices into even layers and pressing them flat so the cream just covers the top.
5. Bake 60–75 minutes, until the surface is deep golden and a knife slides to the bottom with no resistance. Rest 15 minutes before cutting; the gratin needs that time to set into sliceable layers.