Ingredients for - Easy cheesy leeks

1. 1 tbsp olive oil
2. 20g butter , plus extra for the tin
3. 6 leeks , washed and finely sliced
4. 2 garlic cloves , bashed and peeled but left whole
5. 10g thyme sprigs
6. 50g parmesan or vegetarian alternative, finely grated
7. 50g fresh breadcrumbs
8. 20g butter
9. 20g plain flour
10. 300ml whole milk
11. ½ whole nutmeg , grated
12. 1½ tbsp Dijon mustard
13. 75g gruyère or vegetarian alternative, grated
14. 150g mild cheddar , grated

How to cook deliciously - Easy cheesy leeks

1 . Stage

Set a large, deep pan over a medium-low heat and warm the oil and butter. When foaming, add the leeks, garlic and thyme along with a generous pinch of salt.

2 . Stage

Cook for 25-30 mins with the lid on, stirring frequently, until the leeks are completely softened and beginning to caramelise around the edges. Remove the thyme sprigs and discard.

3 . Stage

Meanwhile, make the sauce. Melt the butter in a pan over a medium heat, then stir in the flour. Cook for 1 min. Pour in the milk in a steady stream, whisking constantly, until you have a thick sauce, about 6-8 mins. When it comes to the boil, remove from the heat and stir in the nutmeg, mustard and both cheeses. Season, then stir in the leeks.

4 . Stage

Heat the oven to 200C/180C fan/gas 6. Lightly butter an ovenproof dish around 23cm wide. Mix the parmesan and breadcrumbs with a generous pinch of black pepper.

5 . Stage

Pour the leek mix into the dish. Will keep chilled for up to two days and frozen for up a month. Sprinkle with the parmesan crumbs and bake for 25-30 mins (5 mins longer if chilled, and an extra 10-15 mins from frozen), until golden.