Leeks Mornay
Braised leeks baked under a cheese sauce.
Ingredients
- 6 Leek
- 40 g Butter
- 40 g 00 flour
- 400 ml Milk
- 100 g Gruyere cheese
- ¾ tsp Salt
Method
- Heat the oven to 200C (400F).
- Halve the leeks lengthwise and wash them well, then cook them gently in a little salted water until tender, and drain.
- Meanwhile, melt the butter in a saucepan, stir in the flour, and cook for a minute. Whisk in the milk a little at a time to make a smooth sauce, then melt in most of the grated cheese.
- Lay the leeks in a baking dish, cover with the sauce, and scatter the rest of the cheese on top.
- Bake until golden and bubbling.
- Serve warm.
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About Leeks Mornay
Leeks Mornay, or poireaux gratinés, is a French bistro side that takes tender braised leeks and bakes them under a blanket of cheese sauce until golden and bubbling. It rests on two classic French techniques: gently poaching whole leeks until soft, and building a proper Mornay — a béchamel of butter, flour, and milk enriched with grated Gruyère. Washing the split leeks thoroughly matters, since grit hides between their layers, and cooking them just to tenderness keeps them silky rather than stringy. The gratin is finished with more cheese scattered on top so it browns in the oven.
The dish is comforting and mellow, the sweet, softened leeks melting into the rich, nutty sauce, with a lightly crisp, golden crust where the cheese has caught. It is savory and creamy without being sharp, the Gruyère giving depth rather than tang. Traditionally served as a side alongside roast meats or as part of a winter spread, it can also stand as a light vegetarian main with bread and salad. The care is in the sauce — cooking the flour briefly and whisking in the milk gradually gives a smooth, lump-free Mornay, which is what makes this version worth the oven time.
Leeks Mornay: frequently asked questions
How many calories are in Leeks Mornay?
A serving has about 356 calories — 13.9g protein, 31.7g carbs, 20.1g fat, 2.7g fiber. Figures are estimated from the ingredient amounts and will shift with your portions and brands.
Is Leeks Mornay gluten-free?
As written, no — it contains 00 flour. You'd need a certified gluten-free swap for that ingredient to make it gluten-free.
Is Leeks Mornay dairy-free?
Not as written — it uses Butter, Milk, Gruyere cheese. Swapping those for a plant-based alternative makes it dairy-free.
How long does Leeks Mornay take to make?
About 40 minutes start to finish, but only around 27 of those are hands-on — the rest is largely unattended cooking time you can step away from. In the Homecooked app the timers and parallel steps are sequenced for you so the hands-on part feels even shorter.
How many servings does Leeks Mornay make?
This recipe makes 4 servings. In the app you can scale it up or down and the ingredient amounts adjust automatically.