This article explores the transformative potential of a teacher's identity in the context of bilingual and second language education (SLE) programmes. The first section examines several theoretical options by which this potential might be conceptualised. Drawing on post-structural notions of discourse, subjectivity and performativity, the author emphasises the contingent and relational processes through which teachers and students come to understand themselves and negotiate their varying roles in language classrooms. Simon's (1995) notion of an "image-text" further develops this dynamic, co-constructed understanding and shifts it more specifically towards pedagogical applications: the strategic performance of a teacher's identity in ways that counteract stereotypes held by a particular group of students. These post-structural ideas on teachers' identities are then evaluated in reference to the knowledge base of bilingual and SLE. The author then proposes a "field-internal" conceptualisation by which such theories might be rooted in the types of practices characteristic of language education programmes. The next section of the article describes the author's personal efforts to realise these concepts in practice. "Gong Li--Brian's Imaginary Lover" is a story of how the author's identity became a classroom resource, a text to be performed in ways that challenged group assumptions around culture, gender, and family roles in a community, adult ESL programme serving mostly Chinese seniors in Toronto.