Preheat the oven to 220C/425F/Gas 7.
For the soufflé, mix together the egg yolks and cheese in a bowl, until smooth.
In a separate bowl whisk the egg whites until stiff peaks form when you remove the whisk, and then fold in the yolk mixture, parsley and chives.
Melt the butter in a small ovenproof frying pan and gently pour in the egg mixture. Place into the oven to bake for four minutes, or until risen and golden.
For the gravy, place the onion, wine, butter and stock into a pan and bring to the boil. Reduce the heat and simmer for 4-5 minutes or until thickened.
To serve, place the soufflé onto a plate and pour the gravy over.
