This dissertation examines the need for social justice-oriented teachers to engage in critical collective inquiry about systemic racisms and coloniality/modernity in educational contexts across geopolitical borders. By creating an inquiry community with thirteen Mexican teachers from Mexico and the United States, this study disrupts the historically segregated ways in which racial issues have been examined in both countries, and highlights the similar struggles teachers experience in this colonial/modern world-system. The study uses methodological orientations of practitioner inquiry (Cochran-Smith & Lytle, 2009), pláticas (Flores & Morales, 2021), and research work as healing (Anzaldúa, 2015), which is a methodological finding of this research. Key findings reveal that teachers experience profound isolation both in their professional settings and personal lives, especially regarding their mestizaje. They require dedicated spaces to grapple with the contradictions in their individual and collective histories, and with the traumas inflicted by coloniality/modernity. Teacher education emerged as an emotional, healing, and spiritual process that led them into Nepantla--a transformative liminal space (Anzaldúa, 2015). Teachers inquired coloniality/modernity in education by its deep-seated effects on their self. This study recommends that educational policies on decolonial intercultural education shift the focus from solely cognitive or technical approaches, to those that integrate spiritual and affective dimensions. For practitioner inquiry, the study implies that teachers’ self-inquiry should be recognized as the primary site of knowledge creation. Inquiry processes must extend beyond classroom practices to include personal, familial, and emotional dimensions. Decolonial literacies emerged as practices that integrate language with embodied, historical, healing and spiritual experiences. Such literacies challenge dominant discourses by reasserting non-rational ways of knowing. This dissertation proposes a Pedagogy of Mestizaje in teacher education that reconceptualizes mestizaje as a dynamic space for ontoepistemic and pedagogical transformation (Anzaldúa, 2015). It problematizes the historical use of mestizaje as a tool for homogenization and erasure (Segato, 2021, 2022) while reclaiming it as a site for resistance and renewal. The pedagogy foregrounds teachers’ embodied experiences and ancestral knowledge as central to their craft of a decolonial educational practice. It calls for educational spaces where teachers critically interrogate their self and histories, fostering healing and relationality.