Broccoli and potato gratin

500g/1 lb 2oz potatoes, peeled and chopped

800g/1 lb 12oz broccoli, cut into florets

2 eggs, separated

100g/3½ oz grated cheddar cheese

4 tbsp creme fraiche

Salt, pepper

A few slices of butter

Directions

Step 1

Put the potatoes and broccoli in a large pan, cover with boiling water and cook until tender. Drain and mash.

Step 2

Season well with salt and pepper, then stir in the egg yolks, creme fraiche and half of the cheddar.

Step 3

Beat the egg whites until firm and gently stir in to the mixture.

Step 4

Preheat the oven to 220°C/fan 200°C and lightly grease an ovenproof dish.

Step 5

Put the mixture in and level the surface. Put a few slices of butter on top, sprinkle with the remaining cheese and bake for 20-25 mins until golden.