directions

Preheat the oven to 200C/400F/gas mark 6. Bring a large pan of water to the boil. Boil the cauliflower florets for 5 minutes. After 3 minutes add the broccoli then drain both. To make the sauce, melt the butter in a medium- sized pan. Spoon in the flour and stir for about a minute, without allowing it to brown. Remove from the heat and gradually beat in the milk, a few spoonfuls at a time at first, then increasing the flow as the sauce thins. Once all the milk has been added bring the sauce up to the boil, stirring constantly then remove from the heat. Finally stir in the cheese and mustard and season with a little salt and pepper. Place the broccoli and cauliflower in an oven-proof dish and pour over the sauce. Finish with a sprinkling of cheese and bake in the oven for 20 minutes until golden brown.