Cauliflower and macaroni cheese

Method

1. Preheat the oven to 200°C/fan180°C/ gas 6. Cook the pasta in boiling water for 3 minutes, then add the cauliflower and cook for a further 3 minutes. Drain and return to the pan.
2. Melt the butter in a medium pan. Beat in the flour until a smooth paste. Remove from the heat and gradually beat in the milk until smooth. Return to the heat and bring to a simmer, stirring, until thick enough to coat the back of a wooden spoon.
3. Stir the Cheddar, mustard and half of the Parmesan into the sauce and season well. Pour over the macaroni and cauliflower and fold in the onions. Spoon into a 2-litre ovenproof dish and arrange the tomatoes over the top.
4. Mix the breadcrumbs with the thyme and remaining Parmesan. Sprinkle over the top and drizzle with the extra-virgin olive oil. Bake for 20-25 minutes, until the top is golden and crusty and the filling is bubbling. Stand for 5 minutes before serving.