Description
Indulge in rich, comforting French Onion Scalloped Potatoes made with caramelized onions, creamy sauce, and melted Gruyère. A luxurious side dish perfect for holidays, gatherings, or cozy dinners.
Ingredients
- Russet or Yukon Gold potatoes – thinly sliced for even baking
- Butter – for caramelizing the onions
- Yellow onions – the star of French onion flavor
- Garlic – adds depth and aroma
- Flour – helps thicken the creamy sauce
- Beef broth – gives authentic French onion soup flavor
- Heavy cream – makes the sauce rich and silky
- Gruyère or Swiss cheese – melts beautifully with a nutty flavor
- Salt and pepper – essential seasoning
- Fresh thyme – optional but adds a fragrant touch
You may already have most of these ingredients in your kitchen!
Instructions
- Caramelize the onions
- Heat butter in a large skillet over medium-low heat. Add the thinly sliced onions and cook slowly, stirring occasionally, until they turn golden, soft, and sweet. This step may take 20–25 minutes — the deeper the caramelization, the richer the flavor. Add garlic during the last minute to avoid burning.
- Make the French onion cream sauce
- Sprinkle flour over the onions and stir to coat — this forms the thickening base. Gradually pour in beef broth while stirring, then add heavy cream. Simmer until the sauce becomes smooth, velvety, and slightly thickened. Season with salt, pepper, and fresh thyme.
- Slice the potatoes
- Using a mandoline or sharp knife, slice potatoes thinly and uniformly. Even slices help the dish cook evenly and keep the layers structured.
- Layer everything
- Grease a baking dish. Arrange a layer of sliced potatoes, spoon some of the French onion cream sauce over them, then sprinkle a generous amount of cheese. Repeat layers until all ingredients are used.
- Bake until bubbly
- Cover the dish with foil and bake at 375°F (190°C) for 45–50 minutes or until the potatoes are fork-tender. Remove the foil and bake an additional 15 minutes to brown the cheese and create a bubbly, golden top.
- Cool and serve
- Let the scalloped potatoes rest for 10 minutes before serving. This helps the sauce thicken and the layers stabilize.
Notes
- Low and slow equals flavor: The longer you caramelize the onions, the richer the dish becomes.
- Use Gruyère for best melt: Swiss works too, but Gruyère adds a classic nutty French flavor.
- Mandoline = perfect slices: Ensures even cooking and beautifully stacked layers.
- Add thyme sparingly: A little goes a long way — it enhances without overpowering.
- Make ahead option: Assemble the dish and refrigerate before baking; bake fresh when ready.
- Prep Time: 25 minutes
- Cook Time: 1 hour Total Time: 1 hour 25 minutes