Name: Easy Leek and Ham Gratin with Creamy Béchamel
Prep time: 20 min
Cook time: 35 min
Ingredients: 3 large leeks; 6 slices ham; 1 to 1 ½ cups grated cheese; 12 cups water (for boiling); 1 tablespoon salt (for the cooking water); For the béchamel; 3 ¼ cups milk; 5 tablespoons butter; ½ cup all-purpose flour; ¾ teaspoon salt (plus more to taste); ½ teaspoon black pepper (or to taste); 1 to 2 pinches turmeric (optional); 1 pinch nutmeg (optional)

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This leek and ham gratin is a classic French-style comfort dish made with tender leeks, slices of ham, creamy béchamel, and a golden layer of melted cheese. It is different from a vegetable-only gratin because the ham adds saltiness and protein, while the leeks bring a soft, slightly sweet flavor. I make it when I want something simple, cozy, and satisfying, either as a light main dish or as a rich side for a family meal.

This recipe is based on my YouTube video, with a few adjustments since publication to make the written version more reliable for home cooks in Canada and the USA. In the video, the method is very simple: cook the leeks, roll them in ham, cover with béchamel, add cheese, and gratinate. For the website version, I reduced the roux slightly so the sauce stays creamy instead of pasty, and I lowered the salt because ham and cheese already bring plenty of seasoning.

Why I Make This Recipe This Way

I make it this way because leeks need two things to become delicious in a gratin: enough cooking time and proper draining. If the leeks are undercooked, they stay fibrous. If they are not drained well, they release water into the béchamel and the gratin becomes thin at the bottom.

Easy Leek and Ham Gratin with Creamy Béchamel

I prefer to cook the leeks first in salted water until tender, then let them drain very well before rolling them in ham. The béchamel is thick enough to coat the rolls, but not so thick that it becomes heavy. This is the same idea behind a good vegetable gratin like my creamy cauliflower and potato gratin, where the sauce needs to hold the dish together without hiding the vegetables.

This recipe is also close in spirit to my endive and ham gratin, but the flavor is softer and sweeter because leeks are milder than endives. The endive version has a slightly bitter note, while this leek version is more delicate and creamy.

Ingredients You’ll Need

For the gratin, you need leeks, ham, grated cheese, and béchamel. Choose large leeks if possible, because they are easier to roll and make a better portion. If your leeks are small, use 4 instead of 3.

The béchamel is made with milk, butter, flour, salt, pepper, and a little turmeric for color. Nutmeg is optional. I like a small pinch because it gives that classic French gratin flavor, but if you do not like nutmeg, leave it out.

For the cheese, use something that melts and browns well. Swiss cheese, Gruyère-style cheese, cheddar, mozzarella, or a blend all work. I prefer a cheese with some flavor because the leeks are mild.

If you want to understand the sauce technique more deeply, my guide to silky béchamel sauce explains the roux method and why whisking matters. For a bigger overview of how béchamel fits into classic cooking, you can also read my guide to the French mother sauces.

How to Make Leek and Ham Gratin

Start by trimming the leeks. Remove the tough dark green tops and the root ends, then cut each leek in half lengthwise. Rinse between the layers because leeks often hide sand and soil. This step is important. A beautiful gratin can be ruined by gritty leeks.

Bring a large pot of salted water to a boil. Add the leek halves and cook until tender, about 18 to 20 minutes depending on their size. They should be soft enough to pierce easily with a knife, but not falling apart.

Drain the leeks very well. I like to place them cut side down on a clean kitchen towel or paper towel for a few minutes. This removes excess water and helps the béchamel stay creamy after baking.

To make the béchamel, melt the butter in a saucepan, add the flour, and whisk for about 1 minute without browning. Add the milk gradually while whisking. Cook until the sauce thickens, then season with salt, pepper, turmeric, and nutmeg if using. The sauce should be thick enough to coat a spoon, but still pourable.

Place one leek half on each slice of ham and roll it up. Arrange the rolls in a baking dish. Cover with hot béchamel, sprinkle with grated cheese, and bake until bubbling. If everything is hot when assembled, a quick finish under the broiler works well. If the dish has cooled down or was assembled ahead, bake it first so the center gets properly hot, then broil at the end for color.

This is a rich comfort dish, but it still has a good balance. The leeks bring vegetables and fiber, the ham adds protein, and the béchamel and cheese make it satisfying. It is not a light salad recipe, but it is a good homemade dish when you want something hearty without making a large meat roast.

How This Recipe Is Different From Similar Recipes

This leek gratin is not the same as a potato gratin or a cauliflower gratin. A potato gratin is heavier and starchier, while this one is softer and more vegetable-forward. If you want a potato-based side, my classic pommes boulangères is a better choice because it uses potatoes, onions, and stock instead of béchamel.

It is also different from my classic cauliflower gratin, which has a more neutral vegetable flavor and a firmer texture. This leek version is sweeter, softer, and more elegant.

Compared with broccoli gratin, this dish is less green and less crunchy. Broccoli has more bite when cooked properly, while leeks become tender and almost silky.

This recipe is closer to a traditional ham and vegetable gratin, but the leek makes it feel more French and more seasonal. It is excellent in fall and winter, but because leeks are available most of the year, you can make it any time you want a cozy oven-baked dish.

Tips for Best Results

Do not skip the draining step. Leeks contain a lot of water after boiling. If they go straight from the pot into the ham, the finished gratin can become watery.

Do not oversalt the béchamel. Ham and cheese already contain salt, so the sauce should be seasoned but not aggressive. Taste before adding more.

Use hot sauce over hot or warm leeks if serving right away. This lets you gratinate quickly without drying out the dish.

If making it ahead, assemble the gratin, refrigerate, then bake at 350°F until hot before broiling. This gives a better result than broiling a cold dish for too long.

Substitutions

You can replace regular ham with smoked ham for a stronger flavor. Turkey slices can also work, but they are usually milder and less salty.

For the cheese, use Swiss, Gruyère-style cheese, cheddar, mozzarella, or a simple shredded cheese blend. Stronger cheese gives a more flavorful gratin.

For a vegetarian version, skip the ham and place the cooked leeks directly in the dish. Add a little extra cheese or a few sautéed mushrooms for more depth.

For a richer sauce, replace a small portion of the milk with cream. I would not use all cream because the dish can become too heavy.

For a lighter version, use 2% milk and keep the cheese closer to 1 cup instead of adding a very thick layer.

FAQ

Can I make leek and ham gratin ahead of time?

Yes. Assemble the dish, cover it, and refrigerate. When ready to serve, bake at 350°F until hot in the center, then broil for a few minutes to brown the cheese.

Why is my gratin watery?

The leeks were probably not drained long enough. After boiling, place them on a towel or paper towel for a few minutes before rolling them in ham.

Can I use leftover ham?

Yes. Thin slices work best because they roll easily around the leeks. If using thicker leftover ham, chop it and layer it over the leeks instead.

Can I freeze this gratin?

I do not recommend freezing it. Béchamel can separate after thawing, and leeks can become too soft. It is better fresh or refrigerated for the next day.

What cheese is best?

Swiss-style cheese, Gruyère, cheddar, or mozzarella all work. For the best flavor, use a cheese that melts well and browns nicely.

What to Serve With Leek and Ham Gratin

This gratin can be served as a main dish with a crisp salad, or as a side dish next to roasted meat, chicken, or fish. If you want a potato side, serve smaller portions of the gratin with Lyonnaise potatoes or simple air fryer roasted potatoes.

For a lighter plate, a fresh salad works well. I like the contrast of creamy gratin with a simple acidic salad like a homemade Greek salad.

If you are building a bigger comfort meal, this gratin also pairs well with roasted meats and classic potato dishes. For another cozy oven recipe, try a duck hachis Parmentier on a different night. If you want something with the same béchamel comfort but a completely different flavor, make authentic Greek moussaka.