There’s no “one” correct answer to how long a chef should stay in a given chef job. What’s acceptable and what’s beneficial, to the chef and the employer, will be different according to context and the stage each chef is at in his or her career. Move job too often and your value as a chef will fall, your Chef CV will become ragged. Employers don’t and won’t want to have to go back to square one and look for your replacement in six months time (exception being seasonal operations or fixed term contracts). On the other hand stay too long in the same kitchen and you risk a couple of things, the first is being typecast i.e. he/she is an Accor Chef, or a IHG Chef, or a Hilton Chef. The other risk is that you become a prisoner of your employer. They’ll realise that at a certain point you long passed the optimal time to move and that making an advantageous move would now be very difficult for you. You’re theirs, and all that implies, and the one thing strongly implied here is that you’re going to be taken for granted, and that’s seldom got much in the way of an upside.