Description
These Upside-Down Onion and Gruyere Tarts combine the sweetness of caramelized onions with the rich, nutty flavor of Gruyere cheese atop flaky puff pastry. Drizzled with honey and fresh thyme, they make an elegant appetizer or savory snack that’s both visually stunning and deliciously satisfying.
Ingredients
Scale
Main Ingredients
- 1 sheet puff pastry, thawed
- 1 yellow onion, thinly sliced
- 18 pieces thinly sliced Gruyere cheese (about 1-2 slices per tart)
- 1 egg, beaten (for egg wash)
For Flavoring
- 3 tablespoons honey or homemade hot honey, divided
- Fresh thyme leaves, to taste
- Salt, to taste
- Black pepper, to taste
Instructions
- Preheat and prepare baking sheet: Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper to prevent sticking and for easy cleanup.
- Create honey bases: Drizzle small amounts of hot honey onto the parchment-lined baking sheet, making 9 separate honey spots where each tart will be placed.
- Cut puff pastry: Cut the thawed puff pastry sheet into 9 equal rectangular pieces to serve as the tart tops.
- Assemble tarts: Sprinkle fresh thyme leaves, salt, and black pepper over each honey drizzle on the baking sheet. Then press a thin slice of onion on top of each honey puddle, followed by 1 to 2 thin slices of Gruyere cheese. Carefully place a puff pastry rectangle on top of each onion and cheese stack to form individual tarts.
- Apply egg wash: Brush the top of each puff pastry tart with the beaten egg to promote browning and give them a glossy finish.
- Bake tarts: Transfer the baking sheet to the preheated oven and bake for about 20 minutes, or until the tarts puff up beautifully and turn golden brown.
- Flip and finish: Once baked, remove the tarts from the oven and use a spatula to carefully flip each tart upside down so the onion and cheese side is on top.
- Garnish and serve: Drizzle additional hot honey over each flipped tart and sprinkle with fresh thyme leaves. Let the tarts cool slightly; they are best enjoyed warm.
Notes
- Using homemade hot honey adds a nice spicy sweetness, but regular honey works perfectly fine as well.
- Be careful when flipping the tarts after baking to avoid breaking them—use a wide spatula for support.
- You can prepare the onion slices in advance and keep them refrigerated to save time during assembly.
- These tarts are best served warm for optimal texture and flavor.
- Feel free to substitute Gruyere with other melting cheeses like Emmental or Comté if preferred.
Nutrition
- Serving Size: 1 tart
- Calories: 180
- Sugar: 4g
- Sodium: 210mg
- Fat: 11g
- Saturated Fat: 5g
- Unsaturated Fat: 5g
- Trans Fat: 0g
- Carbohydrates: 15g
- Fiber: 1g
- Protein: 5g
- Cholesterol: 45mg
