Scalloped Potatoes

Method

1. Infuse the cream by combining heavy cream, milk, garlic, thyme, nutmeg, salt, and pepper in a saucepan. Bring to a gentle simmer over medium heat and cook for 5 minutes. The garlic and thyme release their flavors into the fat-rich cream, creating a seasoned liquid that flavors every layer of potato.

2. Butter a 9x13 baking dish. Layer the sliced potatoes in overlapping shingles, slightly fanned. After every 2–3 layers, pour some of the warm cream mixture over and season with a pinch of salt. The layering ensures cream reaches every potato slice, not just the top.

3. Pour the remaining cream over the top layer. The liquid should come about 3/4 of the way up the potatoes — not fully submerged. Top with the grated Gruyère.

4. Cover tightly with foil and bake at 375°F for 45 minutes. The foil traps steam, which cooks the potatoes through gently. Without it, the top browns before the center is tender.

5. Remove the foil and bake 20 minutes more until the Gruyère is golden and bubbling and a knife slides through the center with no resistance. The top should be deeply browned and the cream should be thick and bubbling around the edges.

6. Rest for 10 minutes before serving. The cream thickens as it cools, and the layers set so each portion holds together on the plate.

Equipment

• Mandoline slicer
• Medium saucepan Recommended: Cuisinart Chef's Classic 3-Quart Saucepan
• 9x13 baking dish
• Aluminum foil
• Saucepan Recommended: Cuisinart Chef's Classic 3-Quart Saucepan
• Instant-read thermometer Recommended: ThermoWorks ThermoPop 2

Chef Notes

• The most important thing: Slice the potatoes to a uniform 1/8-inch thickness with a mandoline. Uneven slices mean uneven cooking — thick slices stay raw while thin ones turn to mush. A mandoline is the only tool that gives you the consistency this dish demands.
• Simmer the cream mixture before assembling. Infusing the cream with garlic, thyme, and nutmeg for 5 minutes builds flavor that cold cream poured over raw potatoes can't match.
• Season each layer as you build. Salt between layers ensures the potatoes are seasoned throughout, not just on top.
• Cover with foil for the first 45 minutes to cook the potatoes through, then uncover for the last 20 to brown the cheese. Skipping the foil stage means burnt cheese over raw potatoes.
• Rest for 10 minutes after baking. The cream thickens as it cools slightly, and the layers set so they don't collapse when you serve.

Common Substitutions

Ingredient	Substitution	Notes
Heavy cream	Coconut cream or cashew cream	Coconut adds sweetness. Cashew is most neutral.
Butter	Ghee or olive oil	Ghee for similar richness. Olive oil for dairy-free.
Whole milk	Oat milk or almond milk	Oat milk is creamiest. Almond is thinner — add 1 tsp oil.
Potatoes	Sweet potatoes or cauliflower	Sweet potatoes add sweetness. Cauliflower for low-carb.
Fresh garlic	Garlic powder (¼ tsp per clove)	Fresh is always better but powder works in a pinch.

What You're Practicing

Scalloped potatoes (gratin dauphinois) teach you about cream-based baking — how dairy reduces and thickens around starch, creating a rich, cohesive sauce without a roux. The potato starch itself thickens the cream as it bakes. This same principle applies to any gratin. Visit Mother Sauces for more on cream-based sauces.

Using a mandoline for precision slicing is a professional kitchen skill that applies to any dish requiring uniform thickness — potato chips, vegetable carpaccio, fennel salads, and tarts. Visit Techniques for more on knife skills and precision cutting.