Following the thoughts and topics we have discussed and worked on for a very long time with Bridget Somekh, we would like to present the theoretical relationship between lesson studies, action research and practical knowledge in teacher education. Inspired by the pedagogical philosophy of lesson studies, participatory action research, and core reflection of Korthagen's approach, we have carried out an educational innovation and research project in a master's degree on educational innovation, offered online for Spanish-speaking teachers by three universities in Andalusia (southern Spain). In particular, we analyse the possibilities of lesson studies as an action research model in which observation, action, reflection and cooperation between participants should help to reconstruct the theories in use that teachers count on in their school practice. Let us offer Bridget this brief tribute, from Spain, to thank her and recognise her important work in teaching and cooperation ever since her first visit to Andalusia in 1985. (Contains 1 figure and 7 notes.)