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Rustic Sweet Potato and Caramelized Onion Gruyère Galette

Prep Time 30 minutes
Cook Time 40 minutes
Total Time 1 hour 10 minutes
Servings 6 servings
Calories 450
A savory, flaky galette featuring caramelized onions, sweet potatoes, and melted Gruyère cheese, perfect for a cozy meal or special occasion.

Ingredients

Dough

  • 1 1/4 cups all-purpose flour
  • 1/2 tsp fine sea salt (plus more to taste)
  • 8 tbsp cold unsalted butter, cubed
  • 3–4 tbsp ice water + 1 tsp apple cider vinegar (optional)

Filling

  • 2 tbsp unsalted butter
  • 1 tbsp olive oil
  • 2 large yellow onions (thinly sliced)
  • 2 medium sweet potatoes (about 1 1/2 lb / 680 g, peeled and thinly sliced)
  • 2 cloves garlic (minced)
  • 1–1 1/2 tsp fresh thyme leaves (plus extra for garnish)
  • 1/4 tsp black pepper (+ pinch red pepper flakes (optional))
  • 1 1/2 cups grated Gruyère cheese
  • 1/4 cup grated Parmesan cheese (optional)
  • 1 large egg (for egg wash)
  • 1 tbsp milk or cream (for egg wash)

Finishing

  • Flaky sea salt (for finishing)

Instructions 

  • Pulse flour, salt, and butter until coarse; add water and vinegar to form dough. Chill 30 minutes.
  • Cook onions in butter and oil over medium-low until deep golden, about 25–30 minutes. Add garlic, thyme, salt, and pepper.
  • Roll dough into a 12-inch circle on floured parchment. Spread onions, layer cheese, arrange sweet potatoes, then top with remaining cheese.
  • Fold edges over filling, brush with egg wash, sprinkle thyme and salt. Bake at 400°F (200°C) for 35–40 minutes until golden and tender.

Notes

Chill the dough well for best results and ensure sweet potatoes are sliced evenly for uniform cooking.
Calories: 450kcal
Cost: $15
Course: Main Course
Cuisine: French
Keyword: sweet potato