Caramelized Onion Brie Tarts

5 from 2 votes
Jump to Recipe

This post contains affiliate links. Please read our disclosure policy.

Caramelized onion brie tarts are a delicious appetizer featuring rich, creamy brie cheese and sweet, golden-brown caramelized onions served on crisp, bite-sized crispy puff pastry.

These tarts are our absolute favorite indulgent appetizer for parties and addition to picnics. Brie cheese works as the base for the sweet and succulent caramelized onions and the brie is the boat that holds it all together. Once you have tried these you will be hooked!

Don’t want all the extras in a recipe post? We provide a skip to recipe button in the top left corner, as well as a clickable table of contents, just below, to help make this page easier to navigate.

At Sweet C’s, I add lots of tips in all of my recipes – because I am a home cook without any formal training, and I find I am more confident making dishes when I understand why it works, and what each ingredient means to the flavor of a recipe. My goal is for even the most beginner home cook to feel empowered in the kitchen.

How to Make Sweet Onion Brie Bites

First assemble the following ingredients:

  • Puff pastry (3 sheets) – Puff pastry offers a light, flaky texture with a rich, buttery flavor, serving as a delicate and crisp foundation.
  • Yellow onions (2) – Yellow onions provide a robust, slightly sweet flavor that deepens and sweetens further when cooked, adding a hearty depth to the tarts.
  • Salted butter (2 tbsp) – Salted butter imparts a creamy, rich taste with a subtle hint of saltiness, enhancing the flavors of ingredients.
  • Balsamic vinegar (1 ½ tbsp) – Balsamic vinegar adds a complex, slightly sweet, and tangy flavor with a hint of woodsy richness, ideal for balancing and enhancing savory tarts.
  • Sea salt (? tsp) – Sea salt offers a clean, straightforward saltiness that enhances the natural flavors of ingredients without the bitterness of iodized salt.
  • Brown sugar (½ tsp) – Brown sugar contributes a deep, molasses-like sweetness, adding a rich, caramelized flavor to the onions.
  • Wheel of Brie Cheese (8oz) – Brie cheese is known for its creamy, rich texture and mild, buttery flavor with earthy undertones, making it a versatile and luxurious addition to these tarts.

Once you have assembled the ingredients, use this Method:

A food ingredients on a table.

Prep

Preheat the oven to 400 degrees F. Line a baking sheet with parchment paper or a silicone nonstick baking sheet. Set aside. 

A pot with onions and an egg in it.

Cook Onions

Melt the butter in a small saucepan over medium heat. Add the onions and cook, stirring occasionally, for at least 20 minutes until deeply brown and they smell sweet. Add the balsamic vinegar, salt, and brown sugar. Cook for another 5 minutes to reach a consistency similar to jam. Set aside to cool. 

Four squares of dough on a cutting board.

Cut Pastry

Cut the puff pastry into squares. Use a knife, cut an L shape on the bottom and right hand side. Cut another upside down L shape on the other side of each piece.

A square shaped dough on a wooden board.

Boat Pastry

Gently place the cut corner over the pastry so it rests on the opposite side. Do the same with the other side. This should have a boat-like effect where each tart now has an outer edge to hold the filling in. Brush egg wash around the outside.

A wooden cutting board with a bunch of pastry squares on it.

Add Cheese

Place a piece of brie into each tart square.

A wooden cutting board with a tray of pastries on it.

Top and Bake

Add some caramelized onion on top of the cheese. Place the tarts on the prepared baking sheet then bake for about 20 minutes or until golden brown. Remove the tarts from the oven, some cheese may leak out during cooking which is fine. Enjoy!

Tips and Tricks for Perfect Onion Brie Tarts

Selecting Ingredients: Use good quality puff pastry for the best results. For the onions, choose varieties like Vidalia or Walla Walla, known for their sweetness. The brie should be ripe but firm, making it easier to slice and melt beautifully without becoming too runny.

Caramelizing Onions: Patience is key when caramelizing onions. Cook them slowly over low heat to bring out their natural sugars without burning. Adding a pinch of sugar can accelerate this process, but be careful not to overdo it. Stir frequently to ensure even caramelization.

Seasoning: Enhance the flavors with a sprinkle of fresh thyme or rosemary over the tarts before baking. A light dusting of black pepper can add a subtle heat.

Baking to Perfection: Preheat your oven and bake the tarts until the pastry is golden and puffed, and the brie is just melted. Overbaking can cause the cheese to become too runny and the pastry too hard.

Serving: Serve these tarts warm for the best taste and texture. However, they are also delicious at room temperature, making them a great make-ahead appetizer.

Adding a Glaze: For an extra touch of flavor and shine, brush the caramelized onions with a bit of balsamic glaze before baking.

Variations: Feel free to add other ingredients like chopped nuts for crunch, a sprinkle of blue cheese for a sharper flavor, or even some crispy bacon bits for a savory twist.

Storing and Reheating: If you have leftovers, store them in an airtight container in the refrigerator. Reheat in the oven or toaster oven to maintain the pastry’s crispness.

FAQs

Can I make these tarts ahead of time?

Yes, you can prepare the caramelized onions in advance and store them in the refrigerator for up to 3-4 days. Assemble and bake the tarts shortly before serving for best results.

What type of onion is best for caramelizing?

Sweet onions like Vidalia or Walla Walla are ideal for caramelizing due to their high sugar content. However, regular yellow onions also work well.

How do I prevent the puff pastry from becoming soggy?

Prick the pastry with a fork before adding toppings, which allows steam to escape and keeps the pastry crisp. Also, avoid overloading the pastry with too much topping.

How long does it take to caramelize onions?

It typically takes about 30-45 minutes to properly caramelize onions over low heat. The key is to cook them slowly to bring out their natural sweetness without burning them.

Can I add other ingredients to the tarts?

Absolutely! Feel free to experiment with additions like chopped nuts, bacon bits, or different herbs for varied flavors.

What’s the best way to serve these tarts?

These tarts are best served warm. However, they can also be enjoyed at room temperature, making them a versatile choice for gatherings.

Can I use a different type of cheese?

While brie is a classic choice for its creamy texture, you can use Camembert, goat cheese, or even a sharp cheddar as alternatives.

How should I store leftover tarts?

Store any leftovers in an airtight container in the refrigerator and consume within 2-3 days. Reheat in the oven or toaster oven to maintain the pastry’s crispness.

Try these Appetizers Next

These brie bites are a wonderful accompaniment to Thanksgiving or Christmas dinner table. If you love the flavor combination, try my French Onion Soup or French Onion Chicken next!

If you love this easy recipe please click the stars below to give it a five star rating and leave a comment! Please also help me share on Instagram, Facebook, and Pinterest!

Share on Facebook

Share

Pin this now to find it later

Pin It

Follow on Instagram

Follow

Click here to view the web story for this recipe!

A wooden cutting board with cheese and onion tarts on it.

Only have 30 minutes to get dinner on the table? Sign up for my 30 minute dinner plans direct to your inbox!
Find and shop my favorite products in my Amazon storefront here!

Want to save this recipe?
Just enter your email and get it sent to your inbox! Plus you’ll get new recipes from us every week – and be sure to tag @sweetcsdesigns on social media – I love to see your creations!
5 from 2 votes

Caramelized Onion Brie Bites

By: Courtney O’Dell
Servings: 6 tarts
Prep: 5 minutes
Cook: 1 hour
Total: 1 hour 5 minutes
Onion tarts on a wooden cutting board.
Caramelized onion brie bites on puff pastry are a delectable appetizer, combining the sweetness of slowly caramelized onions with the creamy richness of brie cheese, all nestled atop flaky, buttery puff pastry.

Ingredients 

Instructions 

  • Preheat the oven to 400 degrees F. Line a baking sheet with parchment paper or a silicone nonstick baking sheet. Set aside. 
  • Melt the butter in a small saucepan over medium heat. Add the onions and cook, stirring occasionally, for at least 20 minutes until deeply brown and they smell sweet. 
  • Add the balsamic vinegar, salt, and brown sugar. Cook for another 5 minutes to reach a consistency similar to jam. Set aside to cool. 
  • Cut the puff pastry into squares. Use a knife, cut an L shape on the bottom and right hand side. Cut another upside down L shape on the other side of each piece. See process picture. 
  • Gently place the cut corner over the pastry so it rests on the opposite side. Do the same with the other side. This should have a boat-like effect where each tart now has an outer edge to hold the filling in. 
  • In a small bowl whisk the egg with about 1 tsp of water till frothy.
  • Brush each pastry square with the egg wash. 
  • Place a piece of brie into each tart square then add some caramelized onion on top of the cheese. 
  • Place the tarts on the prepared baking sheet then bake for about 20 minutes or until golden brown. 
  • Remove the tarts from the oven, some cheese may leak out during cooking which is fine. Enjoy!

Nutrition

Serving: 1gCalories: 63kcalCarbohydrates: 4gProtein: 1gFat: 5gSaturated Fat: 3gPolyunsaturated Fat: 0.3gMonounsaturated Fat: 1gTrans Fat: 0.2gCholesterol: 37mgSodium: 91mgPotassium: 70mgFiber: 1gSugar: 3gVitamin A: 157IUVitamin C: 3mgCalcium: 15mgIron: 0.2mg

Nutrition information is automatically calculated, so should only be used as an approximation.

Additional Info

Course: Appetizers
Cuisine: American
Tried this recipe?Mention @sweetcsdesigns or tag #sweetcsdesigns!

About Katherine

You May Also Like

5 from 2 votes (1 rating without comment)

Leave a comment

Your email address will not be published. Required fields are marked *

Recipe Rating




1 Comment

  1. Katherine says:

    5 stars
    Yum!