Preheat the oven to 200C/400F/Gas 6.
Place the egg whites into a large, clean bowl and whisk until stiff peaks form when the whisk is removed. Gradually add the sugar one tablespoon at a time until all the sugar is incorporated and the mixture is glossy.
In a separate bowl, whisk together the egg yolks, melted chocolate and chilli flakes, then gently fold in the egg white mixture.
Heat the oil in a small ovenproof frying pan and add the soufflé mixture to the pan.
Transfer to the oven and bake for eight minutes, or until risen. Serve in the pan.