If you’re craving a tasty starter, these Caramelized Onion Brie Puff Pastry Tartlets are a game-changer! Combining sweet onions and creamy brie, they bring comfort in every bite. Perfect for any occasion, they are easy to make and look stunning. In this post, I’ll share the simple ingredients, step-by-step instructions, and tips to make your tartlets stand out. Get ready to impress your friends and family with this delicious treat!
Ingredients
List of Required Ingredients
– 1 sheet of puff pastry, thawed
– 2 large onions, thinly sliced
– 1 tablespoon olive oil
– 1 tablespoon unsalted butter
– 1 teaspoon granulated sugar
– 1 teaspoon fresh or dried thyme leaves
– 8 oz brie cheese, cut into small cubes
– Salt and freshly cracked pepper to taste
– 1 egg, beaten (for egg wash)
Optional Ingredients
– Balsamic glaze for drizzling
Ingredient Substitutions
You can swap the brie cheese with goat cheese for a tangy taste. For a vegan option, use a plant-based puff pastry and cheese. Instead of thyme, you can try rosemary or oregano for a different flavor. If you do not have sugar, honey can work well to enhance the onions’ sweetness.
Step-by-Step Instructions
Preheating the Oven and Preparing the Baking Sheet
Start by preheating your oven to 400°F (200°C). This helps the pastry cook evenly and puff up nicely. While the oven heats, take a baking sheet and line it with parchment paper. This step keeps the tartlets from sticking.
Caramelizing the Onions
Next, grab a large skillet and add one tablespoon of olive oil and one tablespoon of unsalted butter. Heat this mixture over medium heat. Once the butter melts, toss in two large, thinly sliced onions. Stir them gently every few minutes. You want to cook them for about 15 to 20 minutes until they turn soft and see-through.
After that, sprinkle one teaspoon of granulated sugar and one teaspoon of thyme leaves onto the onions. This adds sweetness and flavor. Keep cooking for another 10 to 15 minutes. Stir often until the onions turn a deep, golden brown. Don’t forget to add salt and pepper to taste. Once done, set the onions aside to cool a bit.
Preparing and Forming the Puff Pastry
Now, let’s get to the puff pastry. Roll out one sheet on a lightly floured surface. Make sure it’s even and not too thick. Use a sharp knife or pizza cutter to slice the pastry into squares, each about 3×3 inches.
Place these squares on your prepared baking sheet. To form a tartlet base, score a smaller square inside each one, about half an inch from the edges. Be careful not to cut all the way through. This will create a border that rises nicely when baked.
Next, add a small cube of brie cheese in the center of each scored area. Spoon the caramelized onions on top of the brie. Make sure to fill each tartlet well.
For that perfect golden look, brush the exposed edges of the pastry with a beaten egg. This step is simple yet important. Finally, bake your tartlets in the preheated oven for 15 to 20 minutes. Look for a puffed, flaky, and golden finish.
After baking, if you like, drizzle some balsamic glaze on top. It adds a nice touch and flavor!
Tips & Tricks
How to Perfectly Caramelize Onions
To caramelize onions well, start with good onions. Yellow onions work best. Slice them thinly for even cooking. Use a mix of olive oil and butter. This mix helps with flavor and browning. Cook on medium heat, stirring often. This process takes time, around 25 to 35 minutes. Be patient. Add granulated sugar after 15 minutes for sweetness. The sugar helps achieve that lovely golden color. Season with salt and pepper to taste. Once done, let them cool slightly before using.
Ensuring Flaky Puff Pastry
A great puff pastry is all about layers. When rolling out the pastry, keep it even and not too thick. Use a lightly floured surface to avoid sticking. After cutting the pastry into squares, score a smaller square inside each. This scoring creates a border that puffs up during baking. Brush the edges with egg wash for a golden finish. Keep your oven hot at 400°F (200°C) for the best puff.
Optimal Baking Times and Temperatures
Baking the tartlets at 400°F (200°C) is key. This high heat puffs the pastry and cooks the filling well. Bake for 15 to 20 minutes. Keep an eye on them after 15 minutes. You want them golden brown and flaky. If you notice uneven browning, rotate the baking sheet halfway through. This tip ensures even baking. Let them cool briefly before serving for the best texture.

Variations
Different Cheese Options
You can use other cheeses besides brie. Cream cheese is a great choice. It has a smooth texture and mild flavor. Goat cheese adds a tangy kick. It pairs well with sweet onions. Cheddar can bring a sharpness to your tartlets. Choose a cheese you love for a tasty twist.
Flavor Enhancements (Herbs and Spices)
Herbs and spices can boost the flavor of your tartlets. Fresh rosemary adds a woodsy note. Basil gives a sweet and aromatic touch. You can also try smoked paprika for a hint of smokiness. Adding a pinch of red pepper flakes adds a bit of heat. Experiment with your favorites to make these tartlets your own.
Alternative Toppings and Drizzles
Get creative with toppings and drizzles. Sliced figs or pears add sweetness and texture. Chopped nuts like walnuts or pecans bring crunch. You can drizzle honey for a sweet finish. A splash of balsamic glaze enhances the flavors. Don’t be afraid to mix and match for fun combinations.
Storage Info
How to Store Leftover Tartlets
To keep your leftover tartlets fresh, place them in an airtight container. You can store them in the fridge for up to three days. Make sure they cool completely before sealing the container. This will help maintain their texture and flavor.
Reheating Instructions
To reheat, preheat your oven to 350°F (175°C). Place the tartlets on a baking sheet. Heat for about 10-15 minutes, or until they are warm and the pastry is crispy again. Avoid using the microwave, as it can make the pastry soggy.
Freezing Options
You can freeze the tartlets if you want to save them for later. Place the cooled tartlets in a single layer on a baking sheet and freeze them for about an hour. Once frozen, transfer them to a freezer bag. They can last for up to two months. When ready to enjoy, bake them directly from the freezer at 400°F (200°C) for about 20-25 minutes.
FAQs
Can I make the tartlets ahead of time?
Yes, you can make these tartlets ahead of time. Prepare the caramelized onions and assemble the tartlets. Cover them and place them in the fridge for up to 24 hours. When ready to serve, bake them directly from the fridge. This keeps the pastry fresh and flaky.
What can I serve with the tartlets?
These tartlets pair well with a simple green salad or a fruit platter. Consider serving them with a light vinaigrette. A glass of chilled white wine also complements the flavors nicely. For an extra touch, you can add a cheese board alongside.
How long do caramelized onions last?
Caramelized onions can last in the fridge for about 5 to 7 days. Store them in an airtight container. If you want to keep them longer, you can freeze them. They freeze well for up to three months.
This blog post covered the key ingredients, steps, and tips for making delicious tartlets. You learned how to create the perfect base with caramelized onions and flaky pastry. Additionally, we explored variations and how to store leftovers for later enjoyment.
In summary, these tartlets are flexible and fun. With simple swaps and tricks, you can make them your own. Enjoy experimenting with flavors and impressing your family and friends!
