Baked Lyonnaise Potatoes

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Lyonnaise potatoes are a classic French side dish that transforms humble ingredients into a savory and comforting meal. Originating from Lyon—a city in France known for its rich culinary traditions—this dish layers tender, golden potatoes with sweet, slow-cooked onions and fragrant herbs. It’s deceptively simple yet delivers big flavor, making it perfect for both weeknight dinners and holiday feasts. The balance of textures is key: soft yet structured potatoes, mellow onions, aromatic herbs, and just enough butter to bring it all together.

This oven-baked version is easy to prep ahead and finishes with a crisp top that’s hard to resist. Traditionally, Lyonnaise potatoes are pan-fried, but I prefer this baked method—it’s more hands-off and still delivers all the flavor and texture. The edges crisp beautifully while the center stays tender.

What You’ll Like About This Recipe

• Classic French flavor made easy. Traditional Lyonnaise potatoes are cooked on the stovetop, requiring attention to avoid burning. This baked version simplifies the method while preserving the essential characteristics—tender potatoes, sweet onions, and herbaceous notes—without requiring constant supervision.
• Caramelized onions add depth and sweetness. Slowly cooking the onions develops layers of flavor you simply can’t get from quick sautéing. The onions soften, mellow, and take on a delicate golden color that weaves through the potatoes, adding richness without relying on cream or cheese.
• Creamy potatoes with crisp edges. Parboiling ensures the potatoes cook evenly, while the oven helps create crisp, golden edges on top. The mix of textures—soft middle layers and crisp upper surface—makes each bite balanced and satisfying.
• Naturally flexible and adaptable. You can customize the herbs, add vegetables like mushrooms, or introduce a bit of cheese for variation without losing the essence of the dish. The foundational flavors are mild, allowing room to adapt to different cuisines or meals.
• A reliable side dish for entertaining. This is the kind of recipe that complements everything from roasted poultry to grilled steak. It also holds up well on a buffet table and reheats reliably, making it ideal for holidays or gatherings where timing matters.

Ingredient Notes

• Onions — Large yellow or sweet onions work best for this dish because they caramelize well and become richly flavored as they cook. Slice them evenly so they soften at the same rate.
• Olive oil and butter — Using both gives the onions depth and prevents burning. Butter adds rich flavor, while olive oil increases the smoke point so the onions cook slowly and evenly.
• Potatoes — Yukon Gold potatoes are ideal because they hold their shape while becoming creamy inside. Their natural starch helps the layers meld together during baking.
• Parsley — Adds fresh, bright flavor to balance the sweetness of the onions. Stir some into the mixture and save a little for garnish.
• Thyme — Fresh thyme leaves add a subtle earthiness that complements the caramelized onions. Dried thyme can be used in a pinch, but use a smaller amount.
• Garlic — A small amount of grated garlic infuses the mixture with gentle savory depth without overpowering the dish.
• Salt and pepper — Season generously so the potatoes are well flavored throughout. Taste the onion mixture before layering to ensure balance.

How to Make It

1. Start by slowly cooking the sliced onions in a mixture of olive oil and butter. Let them soften and become lightly golden over low heat so they develop sweetness without browning too quickly. This step builds the base flavor for the entire dish.
2. Parboil the potato slices briefly to give them a head start. This ensures they bake evenly later and keeps the texture creamy rather than firm or chalky.
3. Toss the warm potatoes with the cooked onions, herbs, garlic, salt, and pepper. Mixing everything while still warm helps the flavors meld together.
4. Transfer the mixture to a buttered baking dish, spreading it into an even layer and gently pressing down so the potatoes settle nicely.
5. Dot the top with butter and bake until the potatoes are tender inside and the top develops a crisp, golden finish.
6. Garnish with fresh parsley for color and serve warm as a hearty French side dish.

Pro Tips

• Parboil the potatoes briefly so they cook evenly in the oven and maintain a tender, creamy texture throughout the dish.
• Slice the potatoes and onions uniformly to ensure consistent cooking and prevent uneven layers or undercooked pieces.
• Reduce the heat or add a splash of water if the onions start browning too quickly; they should soften gradually rather than caramelize deeply.
• Choose a shallow baking dish if you prefer crispier edges, since increased surface area promotes browning.
• Prep the onions and potatoes ahead of time when cooking for holidays or guests; assembling later saves time without affecting quality.

Recipe Variations

• Add cheese for richness. A handful of Parmesan or Gruyère sprinkled over the top during the final minutes of baking creates a lightly crisp, savory crust that complements the onions’ sweetness.
• Make it herb-forward. Increase the parsley and thyme, or fold in rosemary or tarragon for a fragrant variation. This works especially well with roasted chicken or pork.
• Include mushrooms. Sautéed mushrooms add earthiness and moisture, blending seamlessly with the onions and creating a deeper, more savory dish.
• Add a splash of cream. Pouring a small amount of heavy cream over the potatoes before baking enriches the layers without turning the dish into a full gratin.
• Swap shallots for onions. Shallots provide a more delicate, refined sweetness and soften more quickly, giving the dish a slightly more elegant flavor profile.

Serving Suggestions

• Serve with poultry like Creamy Dijon Chicken, Air Fryer Whole Chicken, Duck Confit, Fried Chicken Breasts, or Crispy Skin Chicken Thighs.
• Pair with meats such as Herb-Crusted Beef Ribeye Roast, Instant Pot Boneless Short Ribs, Steak Diane, Hamburger Steaks, or Roasted Rack of Pork with Pan Sauce.
• Add a fish entrée like Baked Chilean Sea Bass, Sole with Parmesan Sauce, Panko Crusted Salmon, or Salmon Fillets with Basil Mayonnaise.

How to Store

• Refrigerate: Store leftovers in an airtight container for up to 4 days. Allow the dish to cool before covering to prevent excess moisture buildup.
• Freeze: Freeze portions in sealed, freezer-safe containers for up to 2 months. Keep portions relatively small for quicker reheating and better texture.
• Reheat: Warm in a 350°F oven until heated through and the top re-crisps. Microwave reheating is faster but will yield a softer texture. Add a small pat of butter when reheating to refresh the dish.