Cheesy Scalloped Potatoes
Thin layers of Yukon Gold potatoes baked in a garlicky cheddar and Gruyère sauce until tender and golden.
These are the potatoes that disappear first at every holiday dinner: tender slices layered with a creamy cheese sauce and baked until the top is brown and bubbling.
Slicing the potatoes thinly and evenly is the one step that matters most. Even slices cook at the same rate, so nothing is crunchy in the middle.
Cheesy Scalloped Potatoes
Ingredients
For the potatoes
- 3 lb (1.4 kg) Yukon Gold potatoes, peeled
- 1½ cups (170 g) shredded sharp cheddar
- 1 cup (100 g) shredded Gruyère
For the sauce
- 4 tbsp (55 g) unsalted butter
- 1 small yellow onion, finely chopped
- 3 garlic cloves, minced
- ¼ cup (30 g) all-purpose flour
- 3 cups (720 ml) whole milk
- 1½ tsp salt
- ½ tsp black pepper
- ½ tsp dried thyme
Instructions
- Heat the oven to 375°F (190°C) and butter a 9 × 13-inch (23 × 33 cm) baking dish.
- Slice the potatoes ⅛ inch (3 mm) thick with a mandoline or a sharp knife.
- Melt the butter in a saucepan over medium heat. Cook the onion for 4 to 5 minutes until soft, then add the garlic for 30 seconds.
- Whisk in the flour and cook for 1 minute. Slowly whisk in the milk and simmer for 4 to 5 minutes until slightly thickened. Stir in the salt, pepper and thyme.
- Mix the cheddar and Gruyère in a bowl.
- Layer a third of the potatoes in the dish, overlapping them. Pour over a third of the sauce and sprinkle with a third of the cheese. Repeat twice more, ending with cheese.
- Cover tightly with foil and bake for 45 minutes.
- Uncover and bake for 30 to 35 minutes more, until a knife slides easily through the potatoes and the top is deep golden.
- Rest for 15 minutes before serving so the sauce thickens.
Tips for success
- Yukon Golds hold their shape and turn creamy. Russets also work but break down more.
- If you use a mandoline, always use the hand guard.
- Put a baking sheet on the rack below to catch any bubbling sauce.
Storing and reheating
Refrigerate covered for up to 4 days. Reheat covered in a 350°F (175°C) oven for 20 to 25 minutes.
Equipment you'll need
- 9 × 13-inch baking dish
- Mandoline slicer (optional)
- Saucepan
Questions
What's the difference between scalloped and au gratin potatoes?
Traditionally, scalloped potatoes are baked in a cream sauce and au gratin potatoes have cheese and often breadcrumbs. Today many recipes, like this one, combine both.
Why are my potatoes still hard?
The slices were probably too thick or uneven, or the dish was uncovered too early. Keep it covered until the potatoes are nearly tender.
Measurements are given in US cups and spoons with approximate metric weights. Oven temperatures can vary, so check doneness using the signs described in each step. Always check labels if you are cooking for someone with a food allergy.
