Classic Scalloped Potatoes with Onions and Cream

Why You’ll Love This Recipe

• Ultra-creamy, cheese-free classic with layers that melt into a silky, spoonable center.
• Slow bake delivers deeply golden edges and a custardy interior—no flour needed.
• Simple ingredient list; a few aromatics build elegant, restaurant-level flavor.
• Make-ahead friendly for holidays, potlucks, and Sunday dinners.

Grocery List

• Produce: Yukon Gold potatoes, yellow onion, garlic, fresh thyme (optional)
• Dairy: Heavy cream, unsalted butter
• Pantry: Kosher salt, black pepper, ground nutmeg (optional), bay leaf (optional)

Full Ingredients

Potatoes and Aromatics

• 3 lb Yukon Gold potatoes, peeled and sliced 1/8 inch thick
• 1 large yellow onion (about 10 oz), thinly sliced into half-moons

Infused Cream

• 2 1/2 cups heavy cream
• 3 cloves garlic, smashed
• 1 3/4 tsp kosher salt (use 1 1/4 tsp if using table salt)
• 3/4 tsp freshly ground black pepper
• 1/4 tsp ground nutmeg (optional but recommended)
• 1 tsp fresh thyme leaves or 1/2 tsp dried thyme (optional)
• 1 bay leaf (optional)

To Finish

• 3 tbsp unsalted butter, softened (for dotting and greasing)
• Additional kosher salt and pepper to season layers, about 1/4 tsp each
• Fresh thyme leaves for garnish (optional)

Step-by-Step Instructions

Step 1: Preheat and prep the dish

Preheat the oven to 325°F (165°C). Generously butter a 3-quart (9×13-inch) baking dish or large oval gratin. For extra flavor, you can rub the dish with a halved garlic clove before buttering. Set the dish on a rimmed sheet pan to catch any bubbling cream.

Step 2: Slice the potatoes and onions

Peel the potatoes and slice them 1/8 inch thick using a mandoline or a sharp knife for even cooking. Keep slices in a bowl as you work to prevent browning, but do not soak for long—excess rinsing reduces the starch that naturally thickens the sauce. Pat dry with a clean towel. Thinly slice the onion into half-moons.

Step 3: Infuse the cream

In a small saucepan, combine the heavy cream, smashed garlic, 1 3/4 tsp kosher salt, black pepper, nutmeg, thyme, and bay leaf. Warm over medium heat until steaming and small bubbles appear at the edges, about 5 minutes. Do not boil. Remove from heat and let steep 10 minutes, then strain or scoop out garlic, thyme stems, and bay leaf. Keep the cream warm.

Step 4: Build the layers

Arrange one-third of the potatoes in the prepared dish, overlapping slightly like shingles. Scatter one-third of the onion over top. Lightly season with a pinch of salt and pepper. Spoon one-third of the warm infused cream evenly over the layer. Repeat for a total of three layers, finishing with cream on top. Dot the surface with the softened butter.

Step 5: Bake low and slow, covered

Cover the dish tightly with foil (grease the underside to prevent sticking). Bake at 325°F (165°C) for 60 minutes, until the potatoes are mostly tender when pierced with the tip of a knife and the cream is gently bubbling.

Step 6: Uncover and brown deeply

Remove the foil, increase the oven temperature to 400°F (200°C), and continue baking 25–35 minutes, until the top is deeply golden and the cream has thickened into a silky sauce. For extra color, broil 1–2 minutes, watching closely.

Step 7: Rest for clean slices

Transfer the dish to a cooling rack and rest for 15 minutes before serving. This crucial pause allows the creamy sauce to set, giving you defined, sliceable layers. Sprinkle with a few fresh thyme leaves and a final crack of pepper, if desired.

Step 8: Serve

Spoon into shallow bowls or slice into squares. Expect a custardy center with tender potato layers and sweet, mellow onion throughout, capped by a beautifully bronzed top.

Pro Tips

• Use Yukon Golds for naturally creamy texture; they hold shape better than russets while still turning silky.
• Do not boil the cream—gentle heat preserves a smooth texture and prevents splitting.
• Grease the foil to keep the top layer from sticking and tearing.
• Resting time matters; it transforms soupy layers into a supple, sliceable casserole.
• Season lightly between layers to ensure every bite is well seasoned, not just the top.

Variations

• Au Gratin Style: Scatter 1 cup grated Gruyère or sharp white cheddar over the top for the last 15 minutes of baking.
• Leek and Bacon: Swap the onion for 2 cups sliced leeks softened in 2 tbsp bacon fat; crumble 4 slices crisp bacon between layers.
• Lighter Cream: Use 2 cups half-and-half plus 1/2 cup heavy cream, and whisk 1 tsp cornstarch into the cold dairy before warming to help it thicken.

Storage & Make-Ahead

Refrigerate leftovers, tightly covered, for up to 4 days. Reheat covered at 350°F (175°C) for 20–25 minutes, then uncover for 5 minutes to re-crisp the top. Make ahead: Assemble up to 24 hours in advance; press parchment directly onto the surface to keep potatoes submerged, cover tightly, and refrigerate. Add 10–15 minutes to the covered bake time. To freeze, bake covered for 45 minutes, cool completely, wrap well, and freeze up to 2 months. Reheat from thawed at 350°F (175°C) until hot and bubbly, 35–45 minutes.

Nutrition (per serving)

Approximate: 440 calories; 32 g fat; 33 g carbohydrates; 6 g protein; 2 g fiber; 550 mg sodium. Values are estimates and will vary with exact ingredients and salt type.