Upside Down Onion Tarts
Flaky, cheesy, and irresistibly savory—your bakery-worthy treat made right at home.
Pastries are my ultimate weakness. Whether sweet or savory, anything wrapped in buttery layers has my full attention. While frequent bakery visits can quickly add up, puff pastry has become my go-to solution for creating indulgent treats in my own kitchen. These Upside Down Onion Tarts are a perfect example—simple to make, stunning to serve, and so delicious you’ll want to keep them in regular rotation.
Ingredients
- 1 box (17 oz) puff pastry, thawed
- 4 tablespoons olive oil
- 2 tablespoons balsamic glaze (premade)
- 1–2 medium sweet onions, sliced into rounds
- 1 teaspoon garlic powder
- Salt and pepper, to taste
- 12 slices Swiss cheese
- ¼ cup shredded Parmesan cheese
- 1 egg white
Instructions
-
Prep the Oven & Pastry
Preheat oven to 400°F (200°C). Line two baking sheets with parchment paper.
Slice puff pastry into squares—typically 6 squares per sheet. Set aside. -
Build the Flavor Base
On each baking sheet, make 6 small pools of olive oil (12 total).
Drizzle a bit of balsamic glaze into each pool. -
Layer the Onions & Cheese
Place one onion slice over each pool. Season with garlic powder, salt, and pepper.
Top each onion with a slice of Swiss cheese and a sprinkle of Parmesan. -
Seal with Pastry
Place a pastry square over each stack, gently pressing and crimping the edges to fully enclose the filling.
Brush the tops with egg white for a golden finish. -
Bake & Flip
Bake for 12–15 minutes, or until pastry is puffed and golden brown.
Let cool for at least 5 minutes before flipping to reveal the caramelized onion base. -
Finish & Serve
Optional: Drizzle with extra balsamic glaze for added depth and shine.
Serve warm and enjoy the layers of flavor and texture.
