Caramelized Onion Brie Tarts
Flaky puff pastry topped with creamy brie and sweet caramelized onions creates these quick, elegant bite-sized appetizers. Perfect for entertaining or a simple snack, they are rich in flavor, satisfying, and easy to prepare.
Equipment
- 1 HexClad Hybrid Nonstick 2-Quart Saucepan with Tempered Glass Lid
- 1 MMmat Silicone Half Sheet Baking Mat (set of 2)
- 1 USA Pan Bakeware Half Sheet Pan (set of 2)
- 1 whisk
- 1 knife
Ingredients
- 3 sheets puff pastry thawed
- 2 yellow onions thinly sliced
- 2 tablespoons salted butter
- 1 ½ tablespoons balsamic vinegar
- ⅛ teaspoon sea salt
- ½ teaspoon brown sugar
- 1 egg
- 1 teaspoon water
- 8 ounces brie cheese wheel
Instructions
- Preheat Oven and Prepare Baking Surface: Preheat your oven to 400°F (200°C) to ensure the puff pastry bakes evenly and turns a golden-brown color. While the oven heats, line a half-sheet pan with parchment paper or a silicone baking mat. This will prevent sticking, make cleanup simple, and provide a stable surface for the pastries to puff evenly during baking.
- Caramelize Onions: Melt 2 tablespoons of salted butter in a medium saucepan over medium heat. Add the thinly sliced yellow onions and stir occasionally to ensure even cooking. Allow the onions to cook slowly for at least 20 minutes until they turn a rich golden-brown color and release a naturally sweet aroma. Patience during this step is crucial, as slow caramelization brings out the deepest, most flavorful sweetness.
- Add Flavor Enhancers: Once the onions are caramelized, stir in 1 ½ tablespoons of balsamic vinegar, ⅛ teaspoon of sea salt, and ½ teaspoon of brown sugar. Continue cooking for an additional 5 minutes, stirring frequently, until the mixture reaches a thick, jam-like consistency. Remove the pan from heat and allow the onion mixture to cool slightly before assembling the tarts.
- Prepare Puff Pastry Base: Take the 3 thawed sheets of puff pastry and place them on a clean work surface. Cut each sheet into squares roughly 3x3 inches. On each square, create an L-shaped cut along the bottom and right-hand side, and an upside-down L on the opposite corners. Fold each cut corner gently over to the opposite side, forming raised edges that will hold the brie and onions in place during baking, creating a small “boat” shape for the filling.
- Make Egg Wash: In a small bowl, whisk together 1 egg and 1 teaspoon of water until the mixture is smooth and frothy. This egg wash will give the pastry a beautiful golden-brown shine, enhancing both flavor and visual appeal. Brushing the edges ensures the tarts look polished and professional once baked.
- Assemble the Tarts: Place each puff pastry square on the prepared baking sheet. Brush the edges of each square with the egg wash to create a glossy finish. Slice the 8-ounce wheel of brie into small pieces or chunks and place one piece in the center of each pastry square. Spoon a generous amount of the caramelized onion mixture over the brie, filling the “boat” without overflowing excessively.
- Bake Until Golden: Transfer the baking sheet to the preheated oven and bake for approximately 20 minutes. Watch as the puff pastry rises and becomes golden-brown, while the brie melts and bubbles slightly. Remove the tarts when they are evenly browned and the filling is hot and creamy.
- Cool and Serve: Carefully remove the tarts from the oven and allow them to cool for a few minutes. Cooling slightly helps the cheese set a little, making the tarts easier to handle. Some brie may have leaked during baking, which is normal and adds a rustic charm. Serve warm as a satisfying appetizer, elegant party bite, or simple snack.
Notes
- Ensure puff pastry is fully thawed before cutting; this prevents cracking and makes folding easier.
- Slice onions thinly for even caramelization and the perfect jam-like texture.
- Stir onions gently but regularly during cooking to avoid burning and ensure uniform sweetness.
- Egg wash is optional but highly recommended for a shiny, golden finish.
- Brie may ooze during baking—this is normal and adds flavor, just place the tarts on a lined baking sheet to catch any overflow.
- Use a sharp knife for clean pastry cuts, and avoid pressing too hard when folding corners.
- Serve immediately for the best texture, though the tarts can be reheated gently.
