Teacher education can benefit directly from experiences in non-formal settings. This article presents a research study with elementary teachers who were teaching in public schools in the state of Nuevo León, México, and participated in a STEM Continuous Professional Development (CPD) workshop. The workshop provided a platform for teachers to interact with scientists and disseminators of science, allowing the appropriation of scientific knowledge applied to everyday activities and settings. Participants improved the quality of their teaching practices in classrooms and gained a new understanding of STEM subjects, enabling them to promote inspiring learning experiences with their students, where dialogue, experimentation and elucidation became an important part of their lessons. The study was carried out using ethnographic tools for analysing recorded videos, 15 sets of field notes, and 49 questionnaires. The sequential analysis of talk and gestures in their participation in the CPD workshop demonstrated high levels of involvement, creativity, and collaborative solution of STEM problems.