The primary focus in UML has been on support for the design and implementation of the software comprising the underlying system. Very little support is provided for the design or evolution of the user interface. This chapter commences with a brief review of UML and its support for user interface modeling. Lean Cuisine+, a notation capable of modeling both dialogue structure and high-level user tasks, is described. It is shown through a case study that Lean Cuisine+ can be used to augment UML and provide the user interface support that is currently lacking.