Cheesy kale gratin

Serves 4-6 You will need:

• Sea salt and freshly ground black pepper • 400g curly kale, stalks removed, leaves thickly shredded (weigh after the stalks are removed) • 25g butter • 25g plain flour • 400ml milk • 250g cheese, grated (use Cheddar cheese, Gruyere cheese or mixed leftover cheese) • 1 teaspoon Dijon mustard

1 You’ll also need an ovenproof gratin dish about 12cm x 20cm. Preheat the oven to 200°C, 400°F, Gas 6.

2 Add 1 teaspoon of salt to a large pot of water, then place the pot on a high heat and bring it to the boil. When it is boiling, add the shredded kale. Cook it for just a couple of minutes until it is almost tender, then drain it and squeeze out all the excess water. Put it into the gratin dish.

3 Next, make the sauce. Heat the butter in a saucepan, add the plain flour and cook for 1 minute until it is bubbling, then, using a whisk, add the milk. Keep whisking and bring to the boil. Remove the saucepan from the heat, then add three-quarters of the grated cheese, the Dijon mustard and season to taste with sea salt and freshly ground black pepper.

4 Pour the cheese sauce over the kale and sprinkle over the remaining grated cheese. Bake the gratin for 15-20 minutes in the preheated oven until it is bubbling and golden.