
Poireaux Et Gruyère Flan
This Flan recipe is a great combination of leeks, eggs, and sumptuous cheese. Easy to make, and (potentially) a great vegetarian dish, too… a quiche by any other name!
Here are more delicious quiche recipes Tasty Spinach Quiche Recipe, Easy Crab Quiche Recipe, or a simple Cheese Omelette.

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About French Flan
Gruyère is a hard yellow cheese, sweet but slightly salty, with a flavor that varies widely with age. It is often described as creamy and nutty when young, becoming more assertive, earthy, and complex with age.
When fully aged (which can take up to a year) it tends to have small cracks which impart a slightly grainy texture. It is traditionally used in French onion soup and Croque-monsieur, but in a quiche such as this it introduces a savoriness without dominating the other ingredients.
Where Does Gruyère Cheese Originate?
Gruyère is named after the town of Gruyères in Switzerland, and originated in the cantons of Fribourg, Vaud, Neuchâtel, Jura, and Berne.
Before 2001, when Gruyère gained Appellation d'Origine Contrôlée (AOC) status as a Swiss cheese, some controversy existed about whether French cheeses of a similar nature could also be labeled Gruyère (French Gruyère-style cheeses including Comté and Beaufort, so if you want to be a purist, then substitute one of those).
Key Ingredients
- shortcrust pastry (store-bought or use my Pate Brisée Recipe)
- leeks
- butter
- crème fraiche, sour cream, or heavy cream
- milk
- eggs
- Gruyère cheese
How To Make French Flan
- Roll out the pastry on a floured surface to about 3mm/1/8in. thickness, and use it to line a 23cm/9in. flan case, ensuring that the lining comes up above the top of the case (do not trim it).
- Line with foil and then rice, pasta, or ceramic beans, and bake blind for 10 minutes.
- Remove the foil and its contents, and bake for a further 4 minutes.
- Meanwhile, cut the leeks into approximately ½cm/1/4in. slices.
- Melt butter in a pan, add the leeks, and stir to coat.
- Cover and cook over on low heat for 8 minutes.
- Uncover and cook for a further 4-5 minutes.
- Lightly beat the crème fraiche, milk, and eggs. Stir in the leeks and most of the cheese, and season well.
- Pour into the flan case.
- Sprinkle with the rest of the cheese and bake for 25 minutes, or until set. (A knife blade, when inserted into the flan filling, careful not to pierce the crust, will come out clean when cooked.)
Substitutions For Gruyère Cheese In French Flan
These substitutions may change the flavor of the finished dish, but are still delicious!
- Cheddar
- Parmesan
- Comté
- Beaufort
Similar Recipes To French Flan
Top Tip
Cook the flan at a low, even temperature to prevent lumping and no peaking while cooking which cools down the oven.
❔FAQ
Traditionally, a flan has very similar ingredients to a quiche or omelette. The basic ingredients are milk or cream, and eggs with various add-ins for flavor. A flan can be made sweet or savory. Some flans also have a pizza-like crust.
Some people would say Mexico, but flan is eaten in many countries with slight variations in each.
A cooked and cooled French flan can be covered with clear wrap and kept in the fridge for up to 3 days.
Yes, A French flan, well wrapped, can be frozen for up to 4 months, but it may not be the same consistency when thawed as before freezing, and the crust may be soggy. Heat from frozen slowly in the oven at 350°F/180°C/Gas 4.
📖 Recipe
Prep Like a Pro
Before you start cooking, chop, measure, and prep every ingredient, and gather your tools.
This simple habit reduces stress, prevents overcooking, and instantly improves your meals. Mise en Place - "Everything in its place."

Traditional French Flan: Leek and Gruyère Flan Recipe
Ingredients
- 500 gr shortcrust pastry shop bought; or use my Pate Brisée recipe
- 400 gr leeks trimmed weight
- 25 gr butter
- 300 gr crème fraiche
- 2 tablespoon milk
- 3 large eggs
- 125 gr Gruyère cheese grated
Instructions
- Roll out the pastry on a floured surface to about 3mm/1/8in. thickness, and use it to line a 23cm/9in. flan case, ensuring that the lining comes up above the top of the case (do not trim it).
- Line with foil then fill with rice, pasta, or ceramic beans, and bake blind for 10 minutes. (The foil and filling (beans) you choose will prevent the crust from bubbling.)
- Remove the foil and its contents, and bake for a further 4 minutes.
- Meanwhile, cut the leeks into approximately ½cm/1/4in. slices.
- Melt the butter in a pan, add the leeks, and stir to coat.
- Cover and cook over on low heat for 8 minutes.
- Uncover and cook for a further 4-5 minutes.
- Lightly beat the crème fraiche, milk, and eggs. Stir in the leeks and most of the cheese, and season well.
- Pour into the flan case.
- Sprinkle on the rest of the cheese and bake for 25 minutes, or until set. (A knife blade when inserted into the flan filling, careful not to pierce the crust, will come out clean when cooked.)









Loved it, tweaked it, or not your "cup of tea"... I’d really love to hear how it went for you.