Moist Leek Tart with Gruyere and Onion
This tart combines the sweetness of caramelized leeks and onions with the nutty richness of Gruyere cheese, baked in a buttery crust until golden. The custard-like filling keeps it moist and delicate, while the Gruyere adds depth. It’s similar to a French quiche, but lighter and more Mediterranean in feel.
⏱ Time
Prep: 20 minutes
Cook: 45 minutes
Total: 1 hour 5 minutes
Ingredients
For the crust (or use store-bought short crust pastry)
1 ¼ cups all-purpose flour
½ tsp salt
½ cup olive oil chilled & cubed
3–4 tbsp ice water
For the filling:
2 tbsp olive oil
2 large leeks (white & light green part only), sliced thinly
1 medium onion, finely sliced
2 cloves garlic, minced
3 large eggs
1 cup heavy cream (or half cream + half milk for lighter version)
1 cup Gruyère cheese, grated (reserve a little for topping)
½ tsp nutmeg (optional, adds warmth)
Salt & black pepper, to taste
Fresh thyme leaves (optional garnish)
Instructions
1. Make the crust
In a bowl, mix flour and salt.
Cut in butter until mixture looks like coarse crumbs.
Add ice water, 1 tbsp at a time, until dough holds together.
Form into a disk, wrap, and chill 30 min. Roll out and line a 9-inch tart pan. Prick with fork and blind bake at 180°C (350°F) for 15 min.
2. Cook the leeks and onion
Heat olive oil in a skillet.
Add sliced leeks and onion, cook gently 8–10 min until soft and lightly golden.
Stir in garlic, season with salt and pepper. Let cool slightly.
3. Prepare the custard
Whisk eggs, cream, nutmeg, salt, and pepper in a bowl.
Stir in grated Gruyère (save 2 tbsp for top).
4. Assemble tart
Spread leek-onion mixture evenly in baked crust.
Pour custard over.
Sprinkle reserved Gruyere on top.
5. Bake
Bake at 180°C (350°F) for 30–35 min, until set and golden.
Let rest 10 min before slicing. Garnish with fresh thyme if desired.
Nutrition information
Calories: ~370
Protein: 12g
Carbohydrates: 24g
Fat: 25g
Fiber: 2g
Sodium: 360mg