It's good to remind people that the Single Responsibility Principle works both ways. A class should have a single responsibility, but also a responsibility should belong to one class. So you already have a chef class, that can cook. You should not have to create separate new classes like "baker" or "mom" or "kitchenhand" that can also cook (unless they are specialised child classes), all of the cooking responsibility should be delegated to the "chef" class.