The purpose of this paper is to describe the Mentored-Teaching Program (MTP), an initiative in the development of graduate student teaching through discipline-based mentored-teaching practice. We begin with a brief overview of what is required to create a seminar in university teaching and the MTP from the departmental perspective. We then turn our focus to the benefits of the MTP for students and teachers specifically from the perspective of the mentor. Finally, the student mentee describes her experiences, applying a theoretical framework taken from the scholarship of teaching and learning in identifying four different lenses from which she came to understand her development as a teacher through this program. Overall, the MTP (in combination with the seminar in University teaching) emphasizes not only the importance of teaching as a collaborative process, but also the importance of combining theory with practice in order to develop into critically reflective teachers.