Caramelized Onion and Gruyère Potato Galette Tips, FAQ & printable recipe

Tips for success

For the crispiest top, use a mandoline to slice the potatoes as evenly as possible. The thinner and more uniform the slices, the more consistent the browning.

Don't overlap the potatoes too much — a slight overlap is fine, but too many layers can trap steam and prevent crisping. Brush each layer with butter as you go, not just the top, to ensure every slice is well-coated.

Let the galette rest for at least 5 minutes after baking before unmolding. This allows the layers to set and makes slicing easier.

If you prefer a softer texture, serve it warm; if you like extra crunch, let it cool for 10 minutes — the top will become even more crackly. Use a serrated knife to cut through the crispy top without squishing the potatoes.

Variations

• Add Bacon: Cook 4 slices of bacon until crisp, crumble, and sprinkle over the onions before adding the potatoes. The smoky flavor complements the sweet onions and Gruyère beautifully.
• Herb Swap: Replace thyme with rosemary or sage. Use 1 teaspoon of finely chopped fresh rosemary or 1/2 teaspoon dried sage. The earthier herbs pair well with the caramelized onions.
• Sweet Potato Twist: Substitute half of the Yukon Gold potatoes with peeled sweet potatoes. The sweet potatoes add a creamy texture and a hint of sweetness that contrasts nicely with the savory cheese.
• Vegan Version: Use a dairy-free butter substitute and omit the cheese, or use a vegan Gruyère-style shreds. The onions and potatoes still create a delicious, savory galette.

Storage and make-ahead

Fridge

Store leftovers in an airtight container in the refrigerator for up to 4 days. Reheat in the oven to restore crispness.

Freezer

Freeze the baked galette, wrapped tightly, for up to 2 months. Thaw overnight in the refrigerator before reheating.

Reheat

Reheat slices in a 375°F (190°C) oven for 8-10 minutes until hot and crispy. Avoid microwaving.

Store leftover galette in an airtight container in the refrigerator for up to 4 days. To reheat, place slices on a baking sheet in a 375°F (190°C) oven for 8-10 minutes, or until heated through and crisp again. Avoid microwaving, which will make the potatoes soggy.

Caramelized onions can be made up to 3 days ahead and stored in the refrigerator. Assemble the galette fully (without baking), cover with plastic wrap, and refrigerate for up to 24 hours. When ready to bake, add 5-10 minutes to the cooking time. You can also bake the galette completely and reheat it in the oven — it keeps well for a day.

Serving ideas

Serve the galette warm, straight from the skillet or flipped onto a platter. It pairs beautifully with a green salad dressed with a simple vinaigrette, or with roasted chicken or steak.

The crispy top and gooey cheese make it a satisfying side dish or a vegetarian main. Garnish with extra thyme and flaky salt just before serving to enhance the flavors.

For a more indulgent presentation, drizzle with a little extra balsamic glaze or a spoonful of crème fraîche. The galette is also delicious at room temperature, making it a great addition to a picnic or brunch spread.

Cut into thin wedges and serve as an appetizer, or larger slices as a main course. It's versatile enough to fit any occasion.

Frequently asked questions

Recipe card

Caramelized Onion and Gruyère Potato Galette

Prep 25 minCook 45 minTotal 1 h 10 minServes 6

Ingredients

• 200 g yellow onions, thinly sliced (about 2 medium)
• 2 tbsp balsamic vinegar
• 50 g unsalted butter, melted (about 3 1/2 tbsp)
• 1 tbsp fresh thyme leaves, plus sprigs for garnish
• 600 g Yukon Gold potatoes, scrubbed (about 4 medium)
• 120 g Gruyère cheese, grated (about 1 1/4 cups)
• 1/2 tsp flaky sea salt, plus more for finishing

Instructions

1. Heat a cast-iron skillet over medium heat and add a small knob of butter. Add the sliced onions and cook, stirring occasionally, until they turn deep golden brown and sweet, about 15 minutes. Pour in the balsamic vinegar and stir to scrape up any browned bits. Cook until the vinegar is absorbed and the onions are jammy. Transfer to a plate and let cool slightly. Wipe the skillet clean.
2. Using a mandoline, slice the potatoes into 1.5 mm thick rounds. Keep them in a bowl of cold water to prevent browning while you work. Drain and pat thoroughly dry with a clean kitchen towel before assembling.
3. Melt the remaining butter and stir in the fresh thyme leaves and a pinch of flaky salt. Set aside.
4. Line the cleaned cast-iron skillet with a circle of parchment paper. Spread the caramelized onions evenly over the bottom, then sprinkle with half of the grated Gruyère.
5. Arrange the potato slices in concentric circles over the onions and cheese, overlapping them slightly like shingles. Start from the outer edge and work inward. Brush the potatoes generously with the thyme butter, then sprinkle with the remaining Gruyère and a pinch of flaky salt.
6. Place the skillet in a preheated 400°F (200°C) oven and bake for 45 minutes, until the top potato slices are deeply golden and crisp at the edges, and the bottom is bubbling and caramelized.
7. Remove the skillet from the oven and let cool for 5 minutes. Run a knife around the edge, then carefully invert the galette onto a serving platter. Peel off the parchment. Garnish with fresh thyme sprigs and a sprinkle of flaky salt. Slice into wedges and serve warm.

Contains: milk

Estimated nutrition per serving

Calories

380

Protein

12 g

Carbohydrates

30 g

Fat

24 g

Automatic estimate from the ingredient list, not laboratory-verified.