Cook the pasta according to the packet instructions, less 1 minute. Drain and run under cold water to cool immediately.

Meanwhile, melt the butter in a large, deep frying pan over low heat.

Once the butter has melted, add the flour and stir for 30 seconds until a paste forms.

Pour in about one-quarter of the milk, whisking for 30 seconds until the mixture combines.

Add the remaining milk and whisk over low heat for 5 minutes, until the sauce is thick enough to coat the back of a spoon.

Stir in the stock powder and cheese. Turn off the heat and stir the pasta through. Serve as is or continue with the following steps for extra crunch.

Preheat the oven grill (broiler). Transfer to a baking dish if needed and sprinkle with the panko breadcrumbs. Spray with olive oil.

Grill (broil) for 2–3 minutes until golden (keep an eye on it because it will change to a golden colour quickly!)