Heat oven to 200C/180C fan, and place a baking sheet on the middle shelf.

To prepare the soufflé dish:

Butter the soufflé dish, sprinkle in the panko breadcrumbs and rotate the dish to ensure the dish is evenly coated. Tip out any excess breadcrumbs.

To make the cheese sauce:

1. Melt the butter in a saucepan over a medium heat. Stir in the flour and mustard powder.
2. Cook, stirring, for 1 min.
3. Take off the heat and gradually stir in the milk, mixing it in thoroughly before adding more. Return to a low heat and stir continuously until very thick (around 10 mins)
4. Transfer to a bowl and allow to cool.
5. Once cooled, add the egg yolks into the sauce. Stir in the Picos De Europa, you may leave a few small bits of cheese in the mixture but it should be pretty smooth.

To make the soufflé mixture:

1. Use a clean whisk and clean bowl to beat the egg whites until soft peaks form.
2. Using a metal spoon, fold 1/3 of the whipped whites into the white sauce to loosen the thick sauce. Once incorporated, gently fold the rest of the egg whites. Do not overfold as you risk losing too much precious air! It is fine to have a few white streaks in the mixture.

Baking the soufflé:

1. Spoon the mixture into the dish. The mixture should come up to roughly 2/3 of the dish. If your dish is slightly smaller than the one in this recipe and your mixture nearly reaches the top, run your thumb around the edge to create a ‘top hat’ effect; this ensures the soufflé rises above the rim and doesn’t stick.
2. Place on the baking sheet and bake for 45-50 mins until the top is golden brown, well risen and has a slight wobble. Do not be tempted to peek or open the oven door during cooking time or the souffle will collapse. Serve immediately.

Little tips

Make sure to add the milk very gradually when making the sauce. Using a rubber spatula is a very good way to squash out any lumps of flour before adding more milk. The sauce must be velvety smooth!

The egg whites must not over whisked or folded in too vigorously, causing the air to be knocked out of them.

Do not oven door is opened before the 45 minutes are up or the soufflé will collapse.

There should be a little runny mixture in the very centre of the soufflé, but if it is completely runny inside it will need to cook for longer.

Always check the temperature of your oven with an oven thermometer as a lot of ovens are not properly calibrated.