Most delicious and easy appetizer, this Classic French Onion Tart is so perfect for spring entertaining! Made with only four ingredients and quick to make, you will love throwing this savory tart together for all of your gatherings.
A perfect spring appetizer that you are going to love to make over and over again! This savory tart is made with only four simple ingredients and the purest and most delicious french flavors. Flakey puff pastry is the base for this tart, topped with shredded gruyere cheese, sliced sweet onions and fresh thyme leaves make this Classic French Onion Tart an easy and delicious starter or side for your next gathering.
I love using puff pastry and always keep some on hand to be able to create quick and easy appetizers that feel super fancy but take no time at all to assemble. Another favorite savory tart is our Heirloom Tomato Tart or for something sweet this French Apple Tart can be make with puff pastry as well! .
Puff Pastry-Frozen and store bought puff pastry makes this French Onion Tart so delicious and flakey! If you are ambitious and want to make homemade puff pastry you can, but frozen is as good!
Onions-Sweet yellow onions sliced thin!
Cheese- You can change up the cheese to your liking, but my favorite is shredded Gruyere Cheese paired with the puff pastry and onions. To make this more an Italian profile you could also use parmesan cheese or a mixture of a few cheeses you love together.
Herbs- Fresh thyme leaves adds a delicious flavor, but could also be replaced with fresh rosemary.
- Once the puff pastry is thawed out, roll out a sheet of frozen puff pastry onto a half sheet baking pan that is lined with parchment paper
- Sprinkle the top of the puff pastry sheet with shredded gruyere cheese and fresh thyme leaves leaving a half in around the edge
- Slice the onions and place them on top of the shredded cheese, slightly overlapping
- Brush the edges of the puff pastry with egg wash, fold in the edges and press down with a fork
- Bake the French Onion Tart in the oven for 45-50 minutes or until the puff pastry is gold brown and the onions are fully cooked through
- Serve warm and Enjoy!
Tips and FAQS To Make The Best Onion Tart
Frozen Puff Pastry
I love keeping a box of frozen puff pastry in my freezer for last minute quick and easy appetizers like our favorite Prosciutto Parmesan Twists.
If you are not a lover of Gruyere cheese, replace it with parmesan cheese or spread a thin layer of Boursin Cheese and it will still taste amazing!
I recommend making this tart the day you are going to serve it because the puff pastry will be super fresh and flakey.
If you have left overs, place the slices in a ziplock bag or airtight container and in the refrigerator for 1-2 days. When you are ready to eat it, place it in the oven for 8-10 minutes to crisp up the puff pastry.
Yes! You can definitely use a pie dough instead of the puff pastry but you will not get the same flakey texture.
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Classic French Onion Tart
- 1 Sheet Frozen Puff Pastry
- ½ Cup Shredded Gruyere Cheese
- 1 Teaspoon Fresh Thyme Leaves
- 3 Sweet Yellow Onions sliced thin
- 1 Egg
- 1 Tablespoon Water
- Preheat oven to 375 degrees F and line a half sheet baking sheet with parchment paper
- Take one frozen puff pastry sheet out of the freezer and allow it to come to room temperature for 10 minutes or until soft enough to unroll
- Place the puff pastry on the lined baking sheet and sprinkle with gruyere cheese and thyme leaves leaving ½ inch board on the puff pastry
- Layer the sliced onions (slightly overlapping) over the cheese
- Using a pasty brush, egg wash the boarder of the puff pastry, fold over the edges and press down using a fork
- Bake the French Onion Tart for 45-50 minutes or until the puff pastry is golden brown and the onions are cooked through
- Remove the tart from the oven and serve warm!
- Whisk together the egg and water; set aside