- Melt butter in a saucepan, then add the flour. Stir continuously until a paste forms – this is called a roux. Keep cooking for 1-2 mins until the colour turns light golden.
- Add the milk to the roux gradually, stirring as you go, until you get a smooth sauce. Cook for 2-3 mins, stirring continuously, until the sauce has thickened. Season to taste with salt and pepper.
- Add Korean hot sauce and ⅔ of the grated cheese
- In a large dish layer the cauliflower bechamel and leeks
- Pop the dish in the oven covered for 20 mins at 180
- In a medium bowl, mix the bread crumbs with the oil and chives and the rest of the cheese. Remove the foil from the cauliflower Sprinkle the top of the cauliflower with the buttered breadcrumbs. Bake until the top of the cauliflower gratin is golden brown and bubbly, about 20 to 25 minutes. Let it rest for 5 minutes before serving. Serve hot.