These Caramelized Onion Scalloped Potatoes take a beloved comfort food to an entirely new level. Thinly sliced Yukon Gold potatoes are tossed with nutty Gruyère and sharp Parmesan, then baked over a sweet, buttery layer of deeply caramelized onions. The result is a savory, rich, and utterly luxurious side dish with a creamy texture and an irresistible golden-brown crust.
This layered dish is rich with sweet, savory flavors and finished with a bright sprinkle of fresh rosemary, making it the perfect accompaniment to any holiday feast or Sunday dinner.
Recipe Details
- Flavor Profile: Savory, cheesy, and deeply savory with a prominent sweetness and depth from the caramelized onions. The final touch of rosemary adds a fresh, herbal note.
- Texture: Wonderfully creamy and tender potato slices contrast with the silky-smooth, soft layer of caramelized onions beneath. It features a crisp, golden-brown crust on top from the broiling step.
- Total Time: The total active time is about 25 minutes (mostly for slicing and caramelizing), followed by 55 minutes of baking and broiling time.
- Difficulty: Easy to Moderate. The dish is simple in concept, but requires patience for perfectly caramelizing the onions and attention to detail when slicing the potatoes evenly.
What You’ll Need
To create this incredible layered casserole, you’ll need three main components: a base of tender Yukon Gold potatoes, a blend of Gruyère and Parmesan cheeses for creaminess and flavor, and a generous layer of caramelized onions cooked in olive oil. These components are bound together with a small amount of stock and seasoned simply with salt, pepper, and fresh rosemary.
Ingredient Notes
- Yukon Gold Potatoes – These potatoes are ideal for scalloped dishes because their medium starch content helps them become creamy without completely dissolving. They hold their shape while softening beautifully.
- Gruyère Cheese – A semi-hard, nutty, and savory cheese that melts incredibly well. It provides the signature, gooey, savory richness that defines the best scalloped potatoes.
- Parmesan Cheese – This hard, aged cheese adds a sharp, salty depth to the dish, enhancing the overall savoriness and contributing to the beautiful crust when broiled.
- Stock – A small amount of stock (chicken, beef, or vegetable) provides the necessary moisture at the base of the dish to help steam the potatoes and keep them from drying out during the long bake.
- Extra Virgin Olive Oil – This is used both for caramelizing the onions and for coating the potatoes, which helps prevent the slices from oxidizing and turning grey, especially if prepping ahead.
Add-ins and Substitutions
- Herbs: While fresh rosemary is the perfect finish, you could swap it for a sprinkle of fresh thyme or chives for a slightly different herbal note.
- Cheeses: If you can’t find Gruyère, Swiss cheese is the closest substitute in terms of flavor and meltiness.
- Enrichment: For an even richer dish, you can use heavy cream instead of stock, or a mix of both, though the original recipe is delightfully savory with stock.
- Pepper: The recipe calls for white pepper, which provides heat without visible dark flecks, maintaining the dish’s color. If you don’t have it, a 1/2 teaspoon of freshly ground black pepper works just as well.
How to Make Caramelized Onion Scalloped Potatoes
This recipe involves three distinct phases: caramelizing the onions, preparing the potato layers, and finally, baking and broiling the casserole. Follow these steps precisely to achieve the perfect result.
- Preheat the Oven: Set your oven to 400°F.
- Caramelize the Onions: Heat 1 tablespoon of olive oil on medium-high heat in a heavy-bottomed sauté pan. Add the 4 cups of thinly sliced onions and stir until they are coated in the oil. Cook them for approximately 15 to 20 minutes, stirring frequently, until they are soft and have achieved a deep golden-brown, caramelized color.
- Toss the Potatoes and Cheese: Put the 6 medium peeled and 1/8-inch thick sliced potatoes in a large bowl. Gently toss them with the remaining 1 tablespoon of olive oil, 1/2 cup of grated Gruyère cheese, 1/2 cup of grated Parmesan, 1 teaspoon of kosher salt, and 1/2 teaspoon of white pepper. Pro Tip: If you are preparing this dish ahead of time, ensure the potato slices are thoroughly coated in the olive oil. This simple step is crucial for preventing the starch in the potatoes from oxidizing and turning grey.
- Layer the Casserole: Lightly grease a large gratin dish (2 to 3-quart capacity) or a 9 x 13-inch casserole with 1 teaspoon of butter. Place the fully caramelized onions in a smooth, even layer across the bottom of the prepared dish. Next, arrange the sliced, cheese-coated potatoes in an appealing pattern over the onions.
- Add Stock and Cheese: Pour the 1/3 cup of stock (chicken, beef, or vegetable) evenly over the arranged potatoes. Sprinkle the top with the remaining 1/4 cup of grated Gruyère cheese.
- Bake Covered: Cover the entire casserole dish tightly with aluminum foil and bake for 50 minutes at 400°F, or until the potatoes are fork tender.
- Broil to Finish: Carefully remove the aluminum foil. Place the uncovered dish under the broiler for about 5 minutes, or until the top is lightly browned and bubbly.
- Serve: Remove from the oven and sprinkle the hot potatoes with 1 teaspoon of finely minced fresh rosemary just before serving.
Recipe Tips
- Even Slicing is Key: To ensure all potatoes cook evenly, it’s vital to slice them consistently, ideally about 1/8 inch thick. A mandoline slicer is excellent for this, but a sharp knife and patience work too.
- Don’t Rush the Onions: True caramelization takes time. The 15 to 20 minutes of cooking the onions is essential for developing the deep, sweet flavor that defines this dish. Do not rush this step by turning the heat up too high.
- Check for Tenderness: The best way to know if your potatoes are done after the covered bake is to test a slice with a fork or knife. It should slide in easily with no resistance.
- Watch the Broiler: Broiling happens fast! Stay near the oven and watch closely during the final 5 minutes to prevent the cheese and herbs from burning.
FAQs
- Q: Can I use different types of potatoes? A: Yukon Gold are highly recommended due to their flavor and texture. Russet potatoes can be used, but they tend to absorb more liquid and can fall apart more easily.
- Q: How do I store leftovers? A: Allow the leftovers to cool completely, then cover and refrigerate for up to 3 days. Reheat gently in the oven or microwave.
- Q: Can I skip the stock? A: The stock provides necessary moisture for the potatoes to steam and soften properly during the covered bake. It should not be skipped to ensure the best, creamiest result.
Serving Suggestions
This rich and savory casserole is a show-stopping side dish that pairs wonderfully with robust main courses and light, fresh sides.
- Protein Mains: It’s fantastic alongside roasted chicken, slow-cooked pork roast, or a perfectly seared steak.
- Greens: Balance the richness with a simple, crisp salad dressed with a light vinaigrette.
- Vegetables: Pair it with steamed green beans or roasted asparagus to add a fresh, green element to the meal.
- Bread: A simple, crusty baguette is great for soaking up any remaining savory juices in the dish.
Make This Recipe in Advance
This is a wonderful make-ahead recipe, perfect for entertaining! You can complete the first four steps caramelizing the onions, tossing the potatoes with cheese and oil, layering the dish, and adding the stock up to 24 hours in advance.
Cover the layered casserole dish tightly with plastic wrap and store it in the refrigerator. When you are ready to bake, remove the dish from the fridge while the oven preheats, then proceed with the covered bake, uncovered broil, and finishing steps exactly as directed in the instructions.
Print
Caramelized Onion Scalloped Potatoes (Gruyère and Parmesan)
- Total Time: 80 minutes
- Yield: 8 servings 1x
- Diet: Vegetarian
Description
These Caramelized Onion Scalloped Potatoes take a beloved comfort food to an entirely new level. Thinly sliced Yukon Gold potatoes are tossed with nutty Gruyère and sharp Parmesan, then baked over a sweet, buttery layer of deeply caramelized onions. The result is a savory, rich, and utterly luxurious side dish with a creamy texture and an irresistible golden-brown crust, making it the perfect accompaniment to any holiday feast or Sunday dinner.
Ingredients
For the Caramelized Onion Scalloped Potatoes
- 2 tablespoons extra virgin olive oil, divided
- 4 cups thinly sliced onions, sliced crosswise
- 6 medium Yukon gold potatoes (about 1 1/2 pounds), peeled and sliced 1/8 inch thick
- 3/4 cup grated Gruyère cheese, divided
- 1/2 cup grated Parmesan cheese
- 1 teaspoon kosher salt
- 1/2 teaspoon white pepper (or black pepper if that is what you have)
- 1 teaspoon butter, for greasing the baking dish
- 1/3 cup stock (chicken, beef, or vegetable)
- 1 teaspoon finely minced fresh rosemary
Instructions
Step 1: Preheat the Oven
Set your oven to 400°F.
Step 2: Caramelize the Onions
Heat 1 tablespoon of olive oil on medium-high heat in a heavy-bottomed sauté pan. Add the 4 cups of thinly sliced onions and stir until they are coated in the oil. Cook them for approximately 15 to 20 minutes, stirring frequently, until they are soft and have achieved a deep golden-brown, caramelized color.
Step 3: Toss the Potatoes and Cheese
Put the 6 medium peeled and 1/8-inch thick sliced potatoes in a large bowl. Gently toss them with the remaining 1 tablespoon of olive oil, 1/2 cup of grated Gruyère cheese, 1/2 cup of grated Parmesan, 1 teaspoon of kosher salt, and 1/2 teaspoon of white pepper. Pro Tip: This step is crucial for preventing the starch in the potato slices from oxidizing and turning grey.
Step 4: Layer the Casserole
Lightly grease a large gratin dish (2 to 3-quart capacity) or a 9 x 13-inch casserole with 1 teaspoon of butter. Place the fully caramelized onions in a smooth, even layer across the bottom of the prepared dish. Next, arrange the sliced, cheese-coated potatoes in an appealing pattern over the onions.
Step 5: Add Stock and Cheese
Pour the 1/3 cup of stock (chicken, beef, or vegetable) evenly over the arranged potatoes. Sprinkle the top with the remaining 1/4 cup of grated Gruyère cheese.
Step 6: Bake Covered
Cover the entire casserole dish tightly with aluminum foil and bake for 50 minutes at 400°F, or until the potatoes are fork tender.
Step 7: Broil to Finish
Carefully remove the aluminum foil. Place the uncovered dish under the broiler for about 5 minutes, or until the top is lightly browned and bubbly. Watch closely!
Step 8: Serve
Remove from the oven and sprinkle the hot potatoes with 1 teaspoon of finely minced fresh rosemary just before serving.
Notes
Even Slicing is Key: To ensure all potatoes cook evenly and have a consistent creamy texture, it’s vital to slice them uniformly, ideally about 1/8 inch thick. A mandoline slicer is highly recommended for this.
Make-Ahead Instructions: This dish can be prepped up to 24 hours in advance! Complete steps 1-5 (caramelizing, tossing, layering, and adding stock/cheese), cover tightly, and refrigerate. Remove from the fridge while the oven preheats, then proceed with the covered bake.
Cheese Substitutions: If Gruyère is unavailable, Swiss cheese is the closest substitute in terms of flavor and meltiness. You can also increase the stock to 2/3 cup and use heavy cream instead for a richer dish.
- Prep Time: 25 minutes
- Cook Time: 55 minutes
- Category: Side Dish
- Method: Baking
- Cuisine: American
Nutrition
- Serving Size: 1/8 of recipe
- Calories: 227
- Sugar: 4g
- Sodium: 410mg
- Fat: 14g
- Saturated Fat: 7g
- Unsaturated Fat: 7g
- Trans Fat: 0g
- Carbohydrates: 19g
- Fiber: 2g
- Protein: 7g
- Cholesterol: 22mg
Keywords: caramelized onion scalloped potatoes, gruyere potato casserole, au gratin potatoes, holiday side dish, creamy potato recipe, make-ahead potatoes
