Tarte à l'Oignon Alsacienne
A savory tart from Alsace, featuring a rich custard filling made with caramelized onions, eggs, and cream, all baked in a crisp pastry crust. It's a comforting and flavorful dish, often enjoyed as a light meal or appetizer.
🧂 Ingredients
- 1 roll Shortcrust pastry(ready-made or homemade)
- 4 large Yellow onions(thinly sliced)
- 50 g Butter
- 1 tbsp Olive oil
- 2 large Eggs
- 150 ml Heavy cream
- 100 ml Milk
- to taste Salt
- to taste Black pepper
- 1 pinch Nutmeg(freshly grated)
- 100 g Lardons(optional, cooked until crisp)
👨🍳 Instructions
- 1
Preheat oven to 200°C (400°F). Line a 23-25 cm (9-10 inch) tart pan with the shortcrust pastry. Prick the base with a fork.
💡 Tip: Blind baking the crust for 10-12 minutes until lightly golden can prevent a soggy bottom. - 2
In a large skillet, melt the butter with the olive oil over medium-low heat. Add the thinly sliced onions and cook slowly, stirring occasionally, until they are very soft, translucent, and lightly caramelized. This can take 20-30 minutes. Season with salt and pepper.
💡 Tip: Cooking the onions slowly is key to developing their sweetness and preventing bitterness. - 3
In a separate bowl, whisk together the eggs, heavy cream, and milk. Season with salt, pepper, and a pinch of freshly grated nutmeg.
💡 Tip: Ensure the nutmeg is freshly grated for the best aroma and flavor. - 4
Spread the softened, caramelized onions evenly over the pastry base. If using, scatter the cooked lardons over the onions.
- 5
Carefully pour the egg and cream mixture over the onions and lardons, ensuring it fills the tart evenly.
💡 Tip: Pour slowly to avoid disturbing the onion layer too much. - 6
Bake in the preheated oven for 30-40 minutes, or until the filling is set and the top is golden brown. The center should be just set, not liquid.
💡 Tip: A slight wobble in the center is okay, as it will continue to set as it cools. - 7
Let the tart cool slightly in the pan for about 10-15 minutes before slicing and serving. It can be served warm or at room temperature.
💡 Pro Tips
- ✓For an authentic Alsatian flavor, consider adding a pinch of caraway seeds to the onions while they cook.
- ✓If you don't have shortcrust pastry, a puff pastry can also be used, though it will result in a lighter, flakier tart.
- ✓This tart is excellent served with a simple green salad.
✨ Twist Ideas
Inspiration for your own version of this recipe
- Some recipes include a small amount of grated Gruyère cheese mixed into the custard filling.
- A touch of Dijon mustard can be added to the custard for a subtle kick.