Description
This easy cheesy leeks recipe combines tender, slowly cooked leeks with a creamy, cheesy béchamel sauce, topped with a crunchy parmesan breadcrumb crust. Baked to golden perfection, it’s a comforting vegetarian dish perfect as a side or a light main.
Ingredients
Scale
Leeks and Aromatics
- 1 tbsp olive oil
- 20g butter, plus extra for the tin
- 6 leeks, washed and finely sliced
- 2 garlic cloves, bashed and peeled but left whole
- 10g thyme sprigs
- Generous pinch of salt
Cheese Sauce
- 20g butter
- 20g plain flour
- 300ml whole milk
- ½ whole nutmeg, grated
- 1½ tbsp Dijon mustard
- 75g gruyère or vegetarian alternative, grated
- 150g mild cheddar, grated
- Salt and pepper, to season
Topping
- 50g parmesan or vegetarian alternative, finely grated
- 50g fresh breadcrumbs
- Generous pinch of black pepper
Instructions
- Cook the leeks: In a large, deep pan over medium-low heat, warm the olive oil and 20g butter. Once the butter is foaming, add the finely sliced leeks, whole garlic cloves, thyme sprigs, and a generous pinch of salt. Cover the pan with a lid and cook the leeks for 25-30 minutes, stirring frequently until the leeks are completely softened and starting to caramelise around the edges. Remove and discard the thyme sprigs and garlic.
- Make the cheese sauce: While the leeks cook, melt 20g butter in a separate pan over medium heat. Stir in the plain flour and cook for 1 minute to create a roux. Gradually pour in the whole milk in a steady stream while whisking constantly to prevent lumps. Continue whisking for 6-8 minutes until the sauce thickens and comes to a boil. Remove from heat and stir in the freshly grated nutmeg, Dijon mustard, grated gruyère, and cheddar cheeses. Season with salt and pepper, then fold in the cooked leeks until evenly combined.
- Prepare the baking dish and topping: Preheat the oven to 200°C (180°C fan)/Gas mark 6. Lightly butter an ovenproof dish approximately 23cm wide. In a small bowl, mix the grated parmesan and fresh breadcrumbs with a generous pinch of black pepper to create the topping mixture.
- Assemble and bake: Pour the leek and cheese sauce mixture into the prepared dish, spreading it evenly. Sprinkle the parmesan breadcrumb topping evenly over the surface. Bake in the preheated oven for 25-30 minutes until the top is golden and crispy. If baking from chilled, extend baking time by 5 minutes; if from frozen, bake for an additional 10-15 minutes until heated through and golden.
Notes
- This dish can be prepared in advance and kept chilled for up to two days or frozen for up to a month.
- For a vegetarian version, use vegetarian cheese alternatives as preferred.
- Ensure the leeks are cooked gently and slowly to develop a rich, caramelised flavor.
- The Dijon mustard adds a subtle tangy depth but can be adjusted to taste or omitted if preferred.
- Use fresh breadcrumbs for the best topping texture and flavor.
- Prep Time: 15 minutes
- Cook Time: 55 minutes
- Category: Side Dish
- Method: Baking
- Cuisine: British
Keywords: cheesy leeks, baked leeks, vegetarian side dish, leek gratin, comfort food, easy vegetable bake
