In this article, we share the process of a long-term community-based participatory action research (CBPAR) project working with Quechua communities in Peru to co-create culturally grounded curriculum materials. We show how policy advocacy, collaboration between Indigenous communities, governments, and social organizations can work to systematically address long-standing social justice issues in education. The project, which has been running since 2016, uses an iterative approach to collaboratively develop quality, culturally grounded educational materials that honors students' and parents' lands, identities, cultures, values, needs, and goals. To make these processes scalable, we demonstrate how to identify policy windows and levers for change to bring the knowledge and voices of community members into curriculum content creation, which is historically reserved for people unfamiliar with community realities. We use a multi-pronged, multi-theory, multi-epistemological approach to discuss the practices and considerations we used and learned for forging effective collaborations between community members, educational specialists, and CBPAR researchers, as well as the tensions and issues that have arisen during the project.