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Upside Down Onion Tarts Recipe

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★★★★★

4.8 from 629 reviews

These Upside Down Onion Tarts feature sweet caramelized onions layered with Swiss and Parmesan cheese, all encased in golden, flaky puff pastry. Enhanced with a touch of balsamic glaze and garlic powder, these tarts are perfect as an elegant appetizer or savory snack. They bake to a crisp, golden finish and are served flipped upside down for a beautiful presentation.

Ingredients

Scale

Puff Pastry and Bases

  • 1 17 oz box puff pastry, thawed
  • 4 tablespoons olive oil
  • 2 tablespoons premade balsamic glaze, plus extra for drizzling

Onion Layer

  • 1–2 medium sweet onions, sliced into rounds
  • 1 teaspoon garlic powder
  • Salt and pepper to taste

Cheese Layer

  • 12 slices Swiss cheese
  • ¼ cup shredded Parmesan cheese

Finishing

  • 1 egg white, for brushing

Instructions

  1. Preheat oven: Preheat your oven to 400°F (200°C). Line two baking sheets with parchment paper to prevent sticking and to ensure even baking.
  2. Prepare pastry squares: Cut each puff pastry sheet into six equal squares, creating twelve squares total. Set these aside for assembling the tarts.
  3. Create olive oil and balsamic bases: On each prepared baking sheet, spoon twelve small pools of olive oil (approximately twelve in total across both sheets). Drizzle a small amount of balsamic glaze over each olive oil pool to add sweetness and depth.
  4. Layer onions and season: Place one sweet onion round on top of each olive oil and balsamic pool. Evenly sprinkle garlic powder, salt, and pepper over the onions for enhanced flavor.
  5. Add cheese layers: Place one slice of Swiss cheese on top of each onion round, then sprinkle each with a bit of shredded Parmesan cheese to add richness and a savory touch.
  6. Seal with puff pastry: Carefully place a puff pastry square over each cheese-topped onion stack. Press down firmly around the edges to seal the tarts and prevent filling from leaking out during baking.
  7. Brush with egg white: Lightly brush the surface of each pastry with egg white. This will help the tarts achieve a beautiful golden brown and glossy finish once baked.
  8. Bake the tarts: Bake the prepared baking sheets in the oven for 12-15 minutes, or until the puff pastry is fully puffed and turns a deep golden brown color.
  9. Cool and flip: Remove the tarts from the oven and allow them to cool for about 5 minutes. Carefully flip each tart upside down to reveal the caramelized onion and cheese topping.
  10. Optional glazing: For an extra burst of flavor and attractive presentation, drizzle additional balsamic glaze over the tops of the flipped tarts before serving.

Notes

  • You can add fresh herbs like thyme or rosemary to the onion layer for an aromatic twist.
  • Ensure the puff pastry is properly thawed before cutting to avoid cracking or tearing.
  • Use a sharp knife or pizza cutter for clean pastry squares.
  • Serve these tarts warm for the best texture and flavor.
  • Leftover tarts can be stored in an airtight container in the refrigerator for up to 3 days and reheated in an oven or air fryer to maintain crispness.

Keywords: upside down onion tarts, puff pastry tarts, savory tarts, Swiss cheese tarts, easy appetizer recipes, balsamic glaze tarts, onion cheese pastry

Find it online: https://victoriablair.com/upside-down-onion-tarts-recipe/