Tarte à l'oignon Alsacienne
This savory French onion tart features a rich, creamy filling of caramelized onions baked in a crisp pastry crust. It's a comforting and flavorful dish, perfect as an appetizer or a light meal. The sweetness of the slow-cooked onions balances beautifully with the savory custard.
An original recipe by Forkin
- Total time
- 1 hr 10 min
- Serves
- 6
- Difficulty
- Medium
- Per serving
- 505 kcal
Allergen information: may contain eggs, gluten, and milk. Always check ingredient packaging if you have an allergy.
Mise en place
Ingredients
- 300 gpuff pastry, thawed if frozen
- 750 gonion, thinly sliced
- 30 gunsalted butter
- 200 mlheavy cream
- 2 pcsegg, large
- 0.5 tspnutmeg, freshly grated
- 0.5 tspsalt
- 0.25 tspblack pepper, freshly ground
Equipment
tart pan with removable bottom · large skillet · medium bowl · whisk · oven
The method
Step by step
- 1
Preheat your oven to 190°C (375°F).
About 10 min
- 2
Melt the butter in a large skillet or Dutch oven over medium-low heat.
About 1 min
- 3
Add the sliced onions to the skillet and cook slowly, stirring occasionally, for 20-25 minutes until they are very soft, translucent, and lightly caramelized.
About 25 min
Cook’s note: Do not rush this step; slow cooking develops the onions' sweetness.
- 4
While the onions cook, unroll the puff pastry and fit it into a 24-26 cm (9-10 inch) tart pan with a removable bottom. Trim any excess pastry, leaving a slight overhang.
About 5 min
Cook’s note: You can gently press the pastry edges to create a decorative rim.
- 5
In a medium bowl, whisk together the heavy cream, eggs, nutmeg, salt, and black pepper until well combined.
About 2 min
- 6
Once the onions are cooked, spread them evenly over the bottom of the puff pastry crust.
About 1 min
- 7
Pour the cream and egg mixture over the onions.
About 1 min
- 8
Bake the tart for 35-40 minutes, or until the crust is golden brown and the filling is set and lightly puffed.
About 40 min
Cook’s note: The center should no longer jiggle when gently shaken.
- 9
Remove the tart from the oven and let it cool slightly before slicing and serving.
Per serving
Nutrition
- Calories
- 505.2kcal
- Protein
- 7.8g
- Carbs
- 35.1g
- Fat
- 37.4g
- Fibre
- 3.2g
- Sugar
- 7.5g
Estimated from the recipe’s ingredient quantities. Values can vary with brands and substitutions.
Keep it good
Store leftover tart covered in the refrigerator.
Reheat in a preheated oven at 160°C (325°F) for 10-15 minutes until warmed through, or gently in a microwave.