This longitudinal case study suggests ways to move beyond the reflective process usually associated with post-lesson mentoring conferences by describing the modalities likely to generate real learning/development opportunities. Based on cultural-historical activity theories (CHAT) and using methodologies from sociodiscursive interactionism, this study shows the joint construction of the meaning of teaching experience and proposes aids for developing the pre-service teacher's power to act more effectively in the classroom. It provides a source for transforming the traditional mentoring methods, mediations and arrangements in teacher education. Proposals are made to further professionalise co-operating teachers at the new Graduate Schools of Teacher Education in France.