French Onion Tart

Introduction

A French Onion Tart brings together the deep, sweet flavor of slowly caramelized onions in a flaky, buttery pastry – an irresistible combination that’s as elegant as it is comforting. With its rich aroma and beautiful golden finish, this tart is the ultimate crowd-pleaser for brunches, picnics, or anytime you’re craving a savory treat with a classic French twist.

Deliciously Unique French Onion Tart

What sets this French Onion Tart apart is the careful caramelization of onions paired with a hint of thyme and creamy Gruyère cheese, all nestled in a crisp tart shell. This combination creates a well-balanced flavor profile: savory, sweet, and subtly nutty, with a melt-in-your-mouth texture that will impress any guest—or make a regular weeknight feel special.

Preparing the Perfect Onion Filling

The secret to this tart lies in the low-and-slow cooking of the onions. Sauté them gently until they are golden and richly caramelized, coaxing out all their natural sweetness. A dash of balsamic vinegar or white wine elevates the flavor even further, adding tang to balance the onions’ deep, savory notes. Letting the filling cool slightly before assembling prevents the pastry from getting soggy.

Assembling Your French Onion Tart

Assemble the tart by spooning the caramelized onions evenly into your pre-baked shell, then topping with shredded Gruyère and fresh thyme. A quick bake in the oven transforms the cheese into a bubbly, golden topping. For an extra flourish, garnish with a sprinkle of chives or cracked black pepper just before serving.

Serving Suggestions for a Show-Stopping French Onion Tart

This tart pairs perfectly with a crisp green salad tossed in a light vinaigrette. Try serving individual slices alongside a glass of chilled white wine or even as a sophisticated starter for dinner parties. It’s just as delicious warm as it is at room temperature, making it wonderfully versatile for meal planning and make-ahead lunches.

Nutritional Information and Serving Size

This recipe yields one 9-inch tart, which serves approximately 6 slices. Each serving typically contains around 350–400 calories, depending on the cheese and pastry used. It’s a hearty yet balanced option thanks to the fiber-rich onions and moderate use of cheese.

Deliciously Unique French Onion Tart (Recap)

The French Onion Tart captures all the beloved flavors of French onion soup in an elegant, hand-held form. Its unbeatable contrast of buttery crust and rich, sweet onions make it a surefire favorite for any meal or celebration.

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Instructions

1. Preheat your oven to 400°F. If using homemade tart pastry, press into a 9-inch tart pan and blind-bake for 10 minutes until lightly golden. Let cool.
2. Heat olive oil and butter in a large skillet over medium-low heat. Add the onions and salt. Cook, stirring frequently, until very soft and golden, about 30–35 minutes. Sprinkle in sugar halfway through to help caramelize.
3. Stir in balsamic vinegar (or wine), pepper, and thyme. Cook an additional 2 minutes, then remove from heat and allow to cool slightly.
4. In a bowl, whisk together eggs and cream (or milk).
5. Spread the caramelized onions evenly into the cooled tart shell or puff pastry. Sprinkle Gruyère cheese on top.
6. Pour the egg and cream mixture evenly over the onions and cheese.
7. Bake tart for 18–22 minutes or until the filling is set and the cheese is bubbly and lightly browned.
8. Cool for 10 minutes. Garnish with chopped chives if desired. Slice and serve warm or at room temperature.

Weekly Meal Planning

This French Onion Tart is perfect for weekly meal prep and entertaining. Save and schedule this recipe to plan meals for the week, and let CookifyAI generate smart shopping lists that consolidate ingredients across all your chosen recipes.

Planning Benefits:

– Automatically calculates total ingredient needs across all meals
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Pro tip: When planning a full week of meals, schedule your recipes so CookifyAI can show overlapping ingredients (like eggs or cream) and help you minimize shopping time and food waste.

Cook and Prep Times

Prep Time: 20 minutes
Cook Time: 45 minutes
Total Time: 1 hour 5 minutes