This work on STEAM and education for sustainable development was undertaken across a series of collaborative case studies as formative research on the inclusion of Indigenous technologies and knowledge practices in teacher education. We noted that, despite the current academic imperative to decolonise southern African education, one seldom finds the inclusion of Indigenous technologies and Indigenous heritage practices in the contemporary classroom. Teachers we worked with were highly interested in their Indigenous knowledge heritage. Yet, they reported that they, and the young teachers they work with, simply do not have the heritage knowledge capital to include Indigenous knowledge systems in their teaching. Other challenges they face are the time it takes to engage community knowledge holders, and to find knowledge relating to school subject disciplines. The teachers observed that students prioritise modernity over Indigenous heritage and technologies, often undervaluing the latter as a forgotten past. Three exploratory cases delved into teacher education's response to challenges through co-engaged work, and this paper synthesises the emerging evidence-aiming to refine pedagogical tools for integrating Indigenous knowledge into STEAM education. A cultural-historical approach was used to frame the study and to derive insights and inferences in co-engaged lesson design research with teachers.