The soufflé that you and I have now learned to make is an exquisite breakfast worth waking up a little bit earlier for. When you master all the techniques and it will be very easy for you to make a soufflé, I propose to complicate the task and prepare a soufflé with different fillings: mushrooms, bacon, sun-dried tomatoes, spinach, crab meat, salmon, truffle, shallots or chives, and any other that come to mind. The main rule: they should be added to soufflé finely chopped or puréed and pre-cooked, so as to minimize their liquid content. Otherwise, the soufflé may not rise.