1 Make the cheese sauce base by heating the milk over a medium heat until just simmering.

2 Meanwhile, in a separate saucepan, melt the butter in a medium saucepan over a medium heat until foamy. Add the flour and stir well with a wooden spoon for a minute or two until you have a thick paste. This is the roux, which will thicken the sauce.

3 Remove the milk from the heat and slowly pour it into the butter and flour mix, whisking all the time. When all the milk is added, turn the heat to low and continue whisking until the sauce has thickened. Add the mustard and the grated cheese and continue to whisk over a low heat until all of the cheese has melted and you are left with a gorgeous thick cheese sauce.

4 Remove from the heat and set aside for about five minutes to cool slightly. Whisk in the egg yolks and place in a bowl covered with clingfilm. Chill for at least 15 minutes.

5 To make the soufflés: preheat the oven to 200 degrees,or 180 fan. Grease six 150ml-200ml ramekins or ovenproof dishes with a little butter.

6 Whisk the egg whites with the salt to soft peak. Beat a third of the egg white mix into the cooled cheese sauce, then fold in the remaining egg whites gently. Continue to mix gently until there are no more egg whites visible.

7 Divide the mix between the ramekins, filling each ramekin up about half to three-quarters from the top.

8 Place the soufflés on a baking tray and bake in the preheated oven for 12-15 minutes until golden and puffed up. The soufflés should be completely set around the edges with a slight wobble in the centre.

9 Remove from the oven and serve immediately.