Upside Down Onion Tarts

Upside Down Onion Tarts
Flaky, cheesy, and bursting with savory goodness—these tarts are bakery-quality, yet simple enough to make at home.
I’ve always had a soft spot for pastries—especially when they’re wrapped in golden, buttery layers. Rather than relying on constant bakery runs, puff pastry has become my secret weapon for crafting irresistible treats in my own kitchen. These Upside Down Onion Tarts are one of my favorites: easy to assemble, visually impressive, and downright addictive.
🧾 Ingredients
Ingredient | Amount |
---|---|
Puff pastry (thawed) | 1 box (17 oz) |
Olive oil | 4 tablespoons |
Balsamic glaze (store-bought) | 2 tablespoons |
Sweet onions | 1–2 medium, sliced into thick rounds |
Garlic powder | 1 teaspoon |
Salt & black pepper | To taste |
Swiss cheese | 12 slices |
Parmesan cheese (shredded) | ¼ cup |
Egg white | 1 |
👩🍳 Instructions
1. Preheat & Prepare
Set your oven to 400°F (200°C). Line two baking sheets with parchment paper.
Cut puff pastry into equal squares—usually 6 per sheet—and set aside.
2. Create the Flavor Base
On each prepared baking sheet, make 6 small circles of olive oil (for 12 total).
Drizzle each with a little balsamic glaze.
3. Assemble Onion & Cheese Layers
Place one onion slice in the center of each oil/glaze circle.
Season lightly with garlic powder, salt, and pepper.
Top each with a slice of Swiss cheese and a pinch of shredded Parmesan.
4. Add the Pastry Layer
Lay a puff pastry square over each onion stack, gently pressing around the edges to seal the filling inside.
Brush the tops with egg white to help them turn golden and crisp.
5. Bake & Flip
Bake for 12–15 minutes, or until the pastry is puffed and golden.
Allow to cool for 5 minutes, then carefully flip each tart to reveal the caramelized onion side.
6. Serve & Enjoy
(Optional) Finish with an extra drizzle of balsamic glaze for added richness.
Serve warm and enjoy every flaky, cheesy bite.