Creamy Cauliflower Rigatoni Cheese

Halve any large cauliflower florets, then pop onto a baking tray.
Drizzle with oil, season with salt and pepper, then sprinkle over the dried oregano. Toss to coat, then spread out in a single layer.
When the oven is hot, roast on the top shelf until golden and tender, 15-20 mins. Turn halfway through.

Meanwhile, add the rigatoni to your pan of boiling water and bring back to the boil. Cook until tender, 12 mins.
Once cooked, drain in a colander and pop back in the pan. Drizzle with oil and stir through to stop it sticking together.

While the pasta cooks, heat the oil for the roux (see ingredients for amount) in a large saucepan on medium-high heat.
When the oil is hot, stir in the flour and cook until it forms a paste, 1-2 mins - you've made a roux!
Gradually stir in the water for the sauce (see ingredients for amount), vegetable stock paste and Dijon mustard, then bring to the boil and simmer until thickened, 1-2 mins.

Once the sauce has thickened, stir in the creme fraiche, then remove from the heat.
Add the Cheddar cheese and stir until melted. Taste and season with salt and pepper if needed.
Stir the cooked pasta and roasted cauliflower through the sauce with a splash of water to loosen if you feel it needs it.