Equipment
Ingredients
Main
- 1350 g leeks, trimmed, washed, and halved
- 2 g salt, fine
- 1 g black pepper, ground
- 50 g unsalted butter
- 50 g all-purpose flour
- 425 ml whole milk
- 175 g cheddar cheese, grated
- 25 g parmesan cheese, grated
- 15 g wholegrain mustard
- 15 g dijon mustard
- 5 g english mustard
Topping
- 30 g breadcrumbs
- 25 g cheddar cheese, grated
Nutrition (per serving)
Nutrition is estimated per serving. Nutrients without complete source data are omitted.
Full nutrition
- Calories
- 667 kcal
- Protein
- 25 g
- Carbohydrates
- 71 g
- Fat
- 34 g
- Fiber
- 7 g
- Sugar
- 19 g
- Sodium
- 860 mg
- Saturated Fat
- 19 g
- Monounsaturated Fat
- 9 g
- Polyunsaturated Fat
- 2 g
- Cholesterol
- 91 mg
- Potassium
- 839 mg
- Calcium
- 773 mg
- Iron
- 8.4 mg
- Magnesium
- 132 mg
- Phosphorus
- 517 mg
- Zinc
- 3.1 mg
- Vitamin A
- 596 mcg
- Vitamin C
- 41 mg
- Vitamin D
- 1.7 mcg
- Vitamin E
- 3.9 mg
- Vitamin K
- 162 mcg
- Vitamin B6
- 0.9 mg
- Vitamin B12
- 1.2 mcg
- Thiamin
- 0.47 mg
- Riboflavin
- 0.62 mg
- Niacin
- 2.8 mg
- Folate
- 267 mcg
- Water
- 405 g
Sources: USDA FoodData Central
Method
Preheat the oven to 200°C (400°F).
Boil the leeks in salted water for 3 minutes until they are slightly tender.
Drain the leeks in a colander and rinse them with cold water to stop the cooking process.
Melt the butter in a saucepan over medium heat and whisk in the flour to create a smooth paste.
Slowly pour the milk into the saucepan, whisking constantly to prevent lumps from forming.
Bring the sauce to a boil, then reduce heat and simmer for 2 minutes until thickened.
Stir in the 175g of cheddar, parmesan, and the three types of mustard until the cheese has melted.
Season the sauce with salt and black pepper to taste.
Place the drained leeks into a shallow baking dish.
Pour the prepared mustard sauce evenly over the leeks.
In a small bowl, mix the breadcrumbs with the remaining 25g of grated cheddar.
Scatter the breadcrumb and cheese mixture over the top of the sauce.
Bake in the preheated oven at 200°C (400°F) for 20 minutes.
Chef's Notes
- For exceptionally tender leeks, ensure you trim off the tough dark green tops and thoroughly wash them to remove any grit trapped between the layers.
- When making the béchamel sauce, using cold milk added to the hot roux (butter and flour mixture) can help prevent lumps. Alternatively, ensure your milk is warm but not boiling before adding.
- The combination of three mustards – wholegrain for texture, Dijon for sharpness, and English for a kick – creates a complex flavour profile. Adjust the quantities based on your preference for heat and pungency.
- Don't overcook the leeks in the initial boiling stage; they will continue to cook in the oven. Aim for just tender, so they don't become mushy.
- For an even crispier topping, you can add a tablespoon of melted butter to the breadcrumb and cheese mixture before scattering.
Storage
Refrigerator: 3 days — Store in an airtight container.
Freezer: 1 month — Texture of leeks may soften significantly upon thawing.
Reheating: Reheat in an oven at 180°C (350°F) until bubbling.
Troubleshooting
Cheese sauce is lumpy
Cause: Milk was added too quickly to the roux
Fix: Pass the sauce through a fine-mesh sieve or use an immersion blender
Prevention: Add milk in small increments, whisking thoroughly after each addition
The finished dish is watery
Cause: Leeks were not drained sufficiently after boiling
Fix: Cannot be fixed once baked
Prevention: Press the leeks gently in the colander or pat them dry with a clean towel before assembling
Cultural Context
Leeks have been a staple in British cuisine for centuries, often featured in hearty side dishes and comforting casseroles. This "Leeks with Three Mustards" recipe elevates the humble leek with a rich, creamy sauce and a savory, cheesy topping, making it a popular choice for festive meals and Sunday roasts.
