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overhead shot of black plastic spatula digging into cheesy leeks in baking dish
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5 from 4 votes

Cheesy Baked Leeks

Leeks wrapped in a rich cheesy sauce, then baked in the oven until crisp on the top and oozy underneath. They make the perfect side dish for just about everything!
Prep Time10 mins
Cook Time45 mins
Total Time55 mins
Course: Side Dish
Cuisine: American, British
Servings: 4
Calories: 527kcal
Cost: £2 / $2.50


  • 9" x 9" Baking Dish (or similar size)
  • Large Frying Pan & Wooden Spoon
  • Sharp Knife & Chopping Board
  • Tongs
  • Whisk


  • 6 thin Leeks (approx 2lb/1kg total BEFORE trimming)
  • 1 1/2 cups / 150g Cheddar, grated (save 1/3 for topping)
  • 1 cup / 100g Gruyere, grated (see notes)
  • 2 cups / 500ml Milk, at room temp
  • 3 tbsp Butter
  • 2 tbsp Flour
  • 1 tbsp Dijon Mustard
  • 1 tbsp Olive Oil
  • few pinches of Ground Nutmeg
  • Salt & Black Pepper, as needed


  • Prep Leeks: Dice off the coarse green tough part of the leek (save for making stock if you wish). Keep the root intact and slice in half lengthways. Clean out any dirt under the tap or in a bowl of cold water then thoroughly dry. Trim off the root then season the insides with a good pinch of salt and pepper.
  • Fry: Add 1 tbsp butter and 1 tbsp olive oil to a large pan over low-medium heat. Add leeks (work in two batches, or as many as you can fit) seasoned/flesh side down and gently fry until soft and buttery. Discard any papery outer layers that detach. Really take the time to ensure they soften right through. If your leeks are quite thick consider adding a splash of stock or water, putting on the lid and allowing them to steam through. That or quarter instead of halving them. Place to one side and repeat with second batch, adding a splash more oil if needed.
  • Sauce: Turn heat to a medium and melt in 2 tbsp butter. Stir in 2 tbsp flour to form a paste, then very gradually begin adding in 2 cups/500ml milk, whisking as you go to avoid any lumps forming. Once thickened, add in 1 tbsp dijon mustard, a good few pinches of nutmeg and salt & pepper to taste. Turn off heat then add in 1 cup/100g Gruyere and 1 cup/100g Cheddar and stir until smooth.
  • Bake: Spread a spoonful of cheese sauce in the base of a 9"x9" baking dish. Add 6 leek halves cut side up, pour over sauce, add the remaining leeks on top then pour over the rest of the sauce. Finish with your remaining cheddar and bake in the oven at 200C/390F for 20-25mins or until golden and bubbly.
  • Serve: Allow to rest for 5 or so mins until it cools down, then slice right down the middle. Serve up and enjoy!



a) Pre Cooking Leeks - I like to fry mine before hand to not only soften them, but also to caramelize them and develop more flavour. Because they're so thin frying on a low heat will cook them right through. If you've got fairly large leeks you can either dice them into rounds and fry them that way, you can boil them, or you can fry them to caramelize the flesh then add liquid & a lid to steam them through. They will cook a little more as they bake in the sauce, but most of the cooking is done before hand.
b) Gruyere - This adds a gorgeous nutty flavour to the sauce. You should be able to find it in most stores, but if for whatever reason you can't you can just sub more cheddar.
c) Pre Ahead - You can prep this up to the point of putting it in the oven. Just allow to cool, tightly cover and store in the fridge. Pop in the oven at 190C/375F (slightly lower temp if cooking straight from fridge) and cook until golden and bubbly.
d) Calories - based on sharing between 4 people.


Calories: 527kcal | Carbohydrates: 28.68g | Protein: 25.17g | Fat: 35.26g | Saturated Fat: 19.024g | Polyunsaturated Fat: 2.003g | Monounsaturated Fat: 11.2g | Trans Fat: 0.605g | Cholesterol: 94mg | Sodium: 640mg | Potassium: 483mg | Fiber: 2.7g | Sugar: 11.65g | Vitamin A: 3317IU | Vitamin C: 16.3mg | Calcium: 793mg | Iron: 3.32mg