Research is needed to explain in more depth what happens and why in teacher-researcher collaboration. Previous research on collaboration points out issues such as asymmetric power relations and cultural differences between professions that can potentially cause problems. This paper examines a Swedish action research project in which teachers and researchers worked together to write a textbook for pre-service teacher education. To study the collaboration, theory on recognition was used to interpret how teachers and, to some extent, researchers understand and value themselves and each other's participation and contribution. Data was collected from a two-day dialogue meeting in the middle of the process where teachers and researchers met to discuss their on-going writing. The result shows that, through well-structured dialogues, the participants transformed their understanding and valuing of both themselves and others in relation to the task of producing new didactical knowledge. This is interpreted as transformed self-recognition for the teachers, who started to acknowledge themselves as knowledge producers. This transformation was crucial for developing the mutual recognition through which new didactical knowledge emerged as a result of the collaboration.