Preheat the oven to 200°C/400°F/Gas Mark 6.

Chop the vegetables into bite-sized pieces and add them to a baking dish. Drizzle with oil and sprinkle with salt and pepper.

Roast the vegetables in the oven for 30-35 minutes, or until they are tender and golden brown.

While the vegetables are roasting, cook the pasta according to the package instructions. Drain and set aside.

In a small saucepan, melt the butter over medium heat. Add the flour and whisk until smooth. Cook for 1-2 minutes, stirring constantly.

Slowly add the milk, whisking constantly to prevent lumps. Cook for 2-3 minutes, or until the sauce has thickened.

Add the grated cheese and stir until melted and smooth. Season with salt and pepper to taste.

Add the cooked pasta to the roasted vegetables and mix well. Pour the cheese sauce over the top and stir gently to combine.

Bake in the oven for an additional 10-15 minutes, or until the cheese sauce is golden and bubbly.

Serve hot, garnished with herbs if desired.