Flaky, cheesy, and bursting with savory goodness—these Upside Down Onion Tarts are bakery-quality, yet simple enough to make at home. With golden puff pastry, caramelized onions, and melty cheese, every bite is a perfect balance of crispy, sweet, and savory flavors.
I’ve always had a soft spot for pastries—especially when they’re wrapped in buttery layers of puff pastry. Instead of running to the bakery whenever a craving strikes, I keep frozen puff pastry on hand to whip up easy yet impressive recipes like this one. These tarts look elegant and taste indulgent, but they’re surprisingly simple to prepare.
Perfect for brunch, holiday spreads, or even a cozy weeknight appetizer, Upside Down Onion Tarts are guaranteed to win over guests and family alike.
Ingredients
- 1 box (17 oz) puff pastry, thawed
- 4 tablespoons olive oil
- 2 tablespoons balsamic glaze (store-bought or homemade)
- 1–2 medium sweet onions, sliced into thick rounds
- 1 teaspoon garlic powder
- Salt and black pepper, to taste
- 12 slices Swiss cheese
- ¼ cup shredded Parmesan cheese
- 1 egg white, lightly beaten
Instructions
Step 1 – Preheat and Prepare
Preheat 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.
Step 2 – Create the Flavor Base
On each prepared baking sheet, drizzle 6 small circles of olive oil (12 total). Add a touch of balsamic glaze over each circle to create a sweet and tangy base.
Step 3 – Assemble the Onion & Cheese Layers
Place one thick onion slice in the center of each circle. Sprinkle lightly with garlic powder, salt, and pepper. Top with a slice of Swiss cheese and a pinch of shredded Parmesan.
Step 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 for a glossy, golden finish.
Step 5 – Bake & Flip
Bake for 12–15 minutes, or until the pastry is puffed and golden brown. Allow to cool for 5 minutes, then carefully flip each tart to reveal the beautifully caramelized onion side.
Step 6 – Serve and Enjoy
(Optional) Drizzle with extra balsamic glaze for added richness. Serve warm and enjoy these irresistible savory pastries.
Serving Suggestions
These Upside Down Onion Tarts are incredibly versatile. Serve them as an appetizer for a dinner party, pair them with a fresh salad for a light lunch, or add them to your brunch table for a crowd-pleasing treat. They’re also delicious alongside roasted meats or hearty soups.
Why You’ll Love This Recipe
- Simple yet impressive – Looks like it came straight from a bakery.
- Perfect flavor balance – Sweet onions, tangy balsamic, and savory cheeses.
- Quick to prepare – Only 15 minutes of baking time.
- Crowd-pleaser – Elegant enough for entertaining, but easy enough for everyday meals.
Once you try these Upside Down Onion Tarts, you’ll find yourself making them again and again. The combination of caramelized onions, gooey cheese, and flaky pastry is simply irresistible.