A simple cheesy leeks recipe that’s an ideal vegetable side for a roast dinner or a festive Christmas lunch. Tender leeks are coated in a smooth cheddar sauce, sprinkled with breadcrumbs and Parmesan, then baked until bubbly and golden.
These cheesy leeks also work well on their own with crusty bread for a cozy lunch or as part of a larger holiday spread.
✔️ Why you’ll love this recipe
- Simple, flavourful vegetable side that pairs with many mains.
- Comforting, cheesy sauce that complements the natural sweetness of leeks.
- Quick to prepare and perfect for roast dinners or holiday menus.
- Freezer-friendly and easy to make ahead.
🛒 Ingredients
Leeks – choose thin, young leeks for a tender texture. Remove outer leaves and the tough dark-green tops, keeping the white and pale green parts.
Cheese sauce – butter, plain flour (for a roux), milk, extra-mature cheddar (grated), a pinch of nutmeg, and Dijon mustard to lift the flavour.
Topping – a simple crunchy mix of breadcrumbs and grated Parmesan, plus salt and pepper to taste.
🔪 How to make cheesy leeks
The full recipe card with exact quantities and the step‑by‑step method is included below.
Step 1 — Prepare the leeks: Remove any tough outer leaves and trim the root end. Cut off the dark green tops and rinse the remaining white and pale green parts thoroughly under cold running water to remove grit. Slice into roughly 5 cm (2 inch) pieces.
Tip: Keep the dark green tops to use for homemade stock if you like.
Step 2 — Pre-cook the leeks: Leeks benefit from a short pre-cook to become tender. Boil or steam them for about 5 minutes in salted water, then drain well. This prevents them from remaining chewy after baking.
Step 3 — Make the cheese sauce: Use the classic roux method. Melt butter in a pan, stir in the flour and cook briefly, then whisk in the milk a little at a time until smooth. Cook until the sauce thickens enough to coat the back of a spoon. Remove from the heat and stir in the grated cheddar, a pinch of nutmeg and a teaspoon of Dijon mustard. Season with salt and pepper.
Step 4 — Assemble and bake: Spoon a little cheese sauce into the base of an ovenproof dish to stop the leeks sticking, arrange the pre-cooked leeks in the dish, then pour over the remaining sauce. Sprinkle breadcrumbs and grated Parmesan evenly over the top and bake at around 200°C (180°C fan / Gas 6) for 20–25 minutes until golden and bubbling.
Top tips
- Spoon a small amount of sauce into the dish first to prevent sticking.
- If you prefer a nuttier flavour, pre-cook the leeks by frying in a tablespoon of butter until they begin to caramelise.
- Choose extra-mature cheddar for a stronger, richer sauce that balances the sweet leeks.
🍴 Serving cheesy leeks
Cheesy leeks are a lovely addition to a roast dinner and pair well with roasted or slow-cooked meats and classic sides. Serve them alongside roast lamb, roast beef, carrot and swede mash, Brussels sprouts, honey-roasted carrots and parsnips, roast potatoes or stuffing. They also make an easy mid-week side with sausages or chicken.
📖 Variations
- Add fried, chopped streaky bacon to the cheese sauce for a smoky, meaty version.
- Include broccoli florets (boiled with the leeks) and increase the sauce for a leek-and-broccoli bake.
- For a richer sauce, replace half the milk with double cream.
- Swap cheddar for Stilton or Gruyère for a different cheese profile.
- Stir 1 teaspoon fresh thyme leaves into the cheese sauce with the grated cheese.
🥡 Storage
Make ahead: You can assemble the dish and store it covered in the fridge for up to 3 days before baking.
Reheat: Leftovers reheat well in the microwave or oven until piping hot.
Freeze: Freeze the assembled dish (baked or unbaked) for up to 3 months. Wrap tightly and thaw before reheating or baking.
❓ FAQs
Leeks work beautifully with meats like chicken, ham and lamb, and pair well with cheeses, cream and garlic. Herbs such as thyme and parsley complement leeks, along with a touch of mustard or lemon for brightness.
Yes, leeks can be eaten raw—thinly sliced they add a mild, sweet onion-like crunch—but they are often cooked to soften their texture and bring out their sweetness.
Yes. Assemble up to three days ahead, then bake when needed. You can also freeze the dish for longer storage.
😋 Related recipes
More vegetable sides to try: Roast Courgettes, Roasted Tenderstem Broccoli, Roast Sweet Potatoes, Butternut Squash Gratin, Air Fryer Brussels Sprouts.
Recipe
Simple Cheesy Leeks Recipe
Tender leeks in a smooth cheddar cheese sauce, topped with breadcrumbs and Parmesan, baked until golden and bubbling.
Course: Side Dish | Cuisine: British
Prep time: 15 minutes | Cook time: 20 minutes | Total time: 35 minutes
Servings: 4 | Calories (approx): 325 kcal
Author: Beth Sachs
Equipment
- Chopping board
- Sharp knife
- Saucepan
- Ovenproof baking dish
Ingredients
- 4 leeks (thin leeks are best)
- 30 g butter
- 30 g plain flour
- 350 ml milk
- 100 g extra-mature cheddar, grated
- 1 teaspoon Dijon mustard
- ⅛ teaspoon freshly grated nutmeg
- 2 tablespoons breadcrumbs
- 25 g Parmesan, grated
- Salt and pepper
Instructions
- Preheat the oven to 200°C (180°C fan / Gas 6).
- Prepare the leeks: discard tough outer leaves and the dark-green tops. Rinse the white and pale-green parts under cold running water, then cut into 5 cm pieces.
- Bring a pan of salted water to the boil, add the leeks and return to the boil for 5 minutes. Drain and set aside.
- Make the cheese sauce: melt the butter in a saucepan, stir in the flour and cook for a minute. Gradually whisk in the milk and cook until the sauce thickens and coats the back of a spoon. Remove from the heat and stir in the grated cheddar, Dijon mustard and nutmeg. Season to taste.
- Assemble: spoon about 2 tablespoons of sauce into the base of an ovenproof dish, arrange the leeks on top and pour over the remaining sauce. Sprinkle with breadcrumbs, grated Parmesan and season with salt and pepper.
- Bake for 20–25 minutes until the topping is golden and the sauce is bubbling. Serve hot.
Notes
Top tips:
- Frying the leeks briefly in butter before assembling gives a deeper caramelised flavour.
- For a creamier bake, replace half the milk with double cream.
- Try different cheeses such as Gruyère or Stilton for an alternative flavour profile.
Nutritional information (approximate)
Calories: 325 kcal | Carbohydrates: 29 g | Protein: 16 g | Fat: 17 g | Saturated fat: 8 g | Fiber: 2 g | Calcium: 426 mg