With performativity and evidence-based teaching, the development of action research (AR) by teachers brings tensions and challenges as teachers move outside their comfort zones and question their practice. This article draws on a small-scale research study developed with teachers. It was funded as part of a professional development initiative by a Teaching School Alliance to support partner schools with university support to build teacher-led systematic research into everyday practice. The dataset combined interviews with teachers about their motivations and experiences, field notes from the sessions, the teachers' final written reports and their evaluation surveys about the project. This article offers a unique perspective on teachers as researchers in a "new age" of work-based AR with the risk of research by teachers in schools being regarded as part of an uncritical 'tick box' performative and celebratory culture. However, the authors argue that teacher research can contribute to a transformational approach to professional development working as an antidote and a source of (re)professionalization based on the outcomes of collaboration, reflection and attention to the singularity of their 'contexts-for action' and specific pupils' needs.