Easy French Onion Tart with Puff Pastry – A Savory Delight

This French Onion Tart is a simple yet elegant dish that brings together these flavors with herbs, melted cheese, and a delightful golden crust.

There’s something magical about the rich, caramelized sweetness of onions paired with the buttery flakiness of puff pastry. Whether you’re serving it as a party appetizer, a light lunch, or a comforting dinner, it’s guaranteed to impress.

I have made this countless times, and every slice vanishes in minutes! Let’s dive into this crowd-pleaser.

Check another different idea for your dinner Colorful lentil Salad!

What You’ll Need for This Recipe:

• 1 sheet puff pastry (thawed if frozen)
• 2 large yellow onions (thinly sliced)
• 2 tbsp unsalted butter
• 1 tbsp olive oil
• 1 tsp sugar
• 1/4 tsp salt
• 1/4 tsp black pepper
• 1 tsp fresh thyme (plus extra for garnish)
• 1/4 cup Gruyère cheese (shredded)
• 1 egg (beaten, for egg wash)

Pro Tips:

1. Perfectly Caramelize the Onions: Cook low and slow for deep, sweet flavor—don’t rush this step!
2. Work with Chilled Pastry: Keep the puff pastry cold to ensure a flaky crust.
3. Avoid Soggy Bottoms: Use a fork to dock the pastry base and blind bake it slightly before adding toppings.
4. Customize the Cheese: Gruyère is classic, but blue cheese or goat cheese adds a tangy twist.
5. Prep Ahead: Caramelize onions in advance to save time on busy days.

Tools You’ll Need:

• Skillet
• Rolling pin
• Baking sheet
• Parchment paper
• Pastry brush

Substitutions and Variations:

1. Cheese Options: Swap Gruyère for blue cheese, goat cheese, or vegan cheese.
2. Vegan Version: Use dairy-free butter, cheese, and skip the egg wash.
3. Add Mushrooms: Sautéed mushrooms pair beautifully with the onions.
4. Make It Mini: Cut the pastry into smaller squares for individual tartlets.
5. Include Bacon: Crumbled cooked bacon adds a smoky flavor.

Make-Ahead Tips:

• Caramelize the onions up to 3 days in advance. Store them in an airtight container in the fridge.
• Assemble the tart just before baking for best results.

Continue to Content

Yield: 4-6 servings

French Onion Tart

Print

Say hello the ultimate French onion tart recipe! With sweet onions, Gruyère, and herbs on a golden crust, it’s perfect for any gathering. Try it now and pin for your next cooking session!

Prep Time 15 minutes

Cook Time 40 minutes

Total Time 55 minutes

Ingredients

• 1 sheet puff pastry (thawed if frozen)
• 2 large yellow onions (thinly sliced)
• 2 tbsp unsalted butter
• 1 tbsp olive oil
• 1 tsp sugar
• 1/4 tsp salt
• 1/4 tsp black pepper
• 1 tsp fresh thyme (plus extra for garnish)
• 1/4 cup Gruyère cheese (shredded)
• 1 egg (beaten, for egg wash)

Instructions

1. Preheat and Prep: Preheat oven to 400°F (200°C). Roll out puff pastry on a floured surface and transfer to a parchment-lined baking sheet. Dock the pastry with a fork.
2. Blind Bake: Brush the edges with beaten egg and bake for 10 minutes until lightly puffed.
3. Caramelize Onions: Heat butter and olive oil in a skillet over medium heat. Add onions, sugar, salt, and pepper. Cook slowly, stirring often, until golden brown, about 25 minutes.
4. Assemble the Tart: Spread the caramelized onions over the puff pastry, leaving a 1-inch border. Sprinkle with Gruyère cheese and thyme.
5. Bake and Serve: Bake for another 15 minutes until the cheese is melted and the pastry is golden brown. Let cool slightly, slice, and serve.

Did you make this recipe?

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Tips for Leftovers and Storage

• Store leftover tart in an airtight container in the fridge for up to 3 days. Reheat in the oven for 10 minutes at 375°F to maintain crispness.

Conclusion

This French Onion Tart with Puff Pastry is a guaranteed hit for any occasion. Its elegant look and irresistible flavor make it a crowd-pleaser every time. Gather your ingredients and let the magic happen in your kitchen.

Don’t forget to leave a review sharing your thoughts or any twists you tried—we’d love to hear from you!

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