If you’re looking for a show-stopping yet effortless dish for your next get-together, this classic Onion Tart will be perfect. It’s rich, buttery, and packed with caramelized onion goodness, perfect for impressing guests without breaking a sweat.

Whether you’re hosting a casual brunch, a family gathering, or an elegant cocktail party, this tart fits right in. It’s one of those recipes that make you feel fancy while actually being super simple to prepare!

Caramelized Onion Tart over a rustic wooden cutting board

Why This Onion Tart is a Party Favorite

Easy to make – The steps are simple, and most of the time is hands-off.
Crowd-pleaser – The deep, sweet flavor of caramelized onions with a crispy, buttery crust is irresistible.
Versatile – Serve it warm or at room temperature, making it perfect for entertaining.
Great for all occasions – From weekend brunches to wine nights, this tart is always a hit.

Here’s What You’ll Need:

For the Crust

200 g all-purpose flour
100 g cold unsalted butter (cut into cubes)
1 egg
A pinch of salt
1-2 tbsp cold water

Here’s What You’ll Need:

For the Filling

3-4 large onions (about 500 g)
30 g unsalted butter
100 ml heavy cream (20-30%)
2 eggs
100 g hard cheese (such as Gruyère, Parmesan, or Cheddar), grated
Salt and pepper to taste
A pinch of nutmeg (optional)

How to Make Caramelized Onion Tart

1. Make the Crust

In a large bowl, combine the flour, salt, and butter. Rub the mixture with your fingers until it resembles fine breadcrumbs.

Add the egg and cold water, kneading just until the dough comes together.

Shape the dough into a ball, wrap it in cling film, and refrigerate for 30 minutes.

2. Prepare the Filling

Slice the onions into thin half-rings.
Melt the butter in a pan over medium heat and sauté the onions until soft and caramelized (about 20 minutes). Stir frequently to prevent burning.
In a bowl, whisk together the eggs and cream, then add the grated cheese, salt, pepper, and nutmeg. Stir to combine.

3. Assemble and Bake

Roll out the chilled dough and fit it into a tart pan (about 23 cm in diameter). Press the edges and prick the base with a fork.
Pre-bake the crust at 180°C (350°F) for 10 minutes using blind baking (cover with parchment paper and add pie weights or dried beans).
Spread the caramelized onions evenly over the crust, then pour the cheese and cream mixture on top.
Bake for 25-30 minutes until the filling is golden and set.

covered with parchment paper and added dried beans

caramelized onions and cheese cream mixture

caramelized onions and cheese cream mixture on top of the crust

4. Serve and Enjoy

Let the tart cool slightly before slicing. It’s delicious both warm and cold, perfect for serving at a party when you don’t want to be stuck in the kitchen!

caramelized onion tart on a wooden board

sliced caramelized onion tart on a plate

Variations to Try

Want to mix things up? Here are a few ideas:

Add bacon – Crumbled crispy bacon pairs beautifully with the caramelized onions.
Make it vegetarian-friendly – Swap the cheese for a dairy-free alternative and use plant-based cream.
Spice it up – Add a pinch of smoked paprika or thyme for extra depth of flavor.
Try a different cheese – Blue cheese or goat cheese brings a bold twist.
Go mini – Use a muffin tin to create bite-sized tarts for easy serving at parties.

This Onion Tart is a lifesaver when you need something fancy yet easy for your guests. It’s rich, cheesy, and full of that deep caramelized onion flavor that makes everyone go back for seconds.

Serve it at a holiday dinner or just as a snack or meal for yourself, it’s bound to be a favorite. So go ahead, give it a try, you’ll love how simple and delicious it is!

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