Sociocultural theories and Indigenous epistemologies inform approaches to teaching and learning with K-12 multilingual learners and Indigenous students in the United States, and center instruction in the cultural and linguistic identities of children and their communities. Teacher preparation programs often incorporate readings and opportunities for dialogue around these sociocultural concepts, theories, and instructional approaches. However, without opportunities for implementation, it is difficult to know how fully these practices are taken up in classrooms. Challenges to bridging theory into practice include teacher autonomy, agency, and opportunities for practice. With decades of research that support the use of teacher inquiry in general, and collaborative and sustained inquiry in particular, a gap in research remains around what happens when sustained collaborative inquiry is used with teachers of multilingual learners (MLLs) in unique contexts. Using a multi-case study methodology, this study examines what happens when in-service teachers of multilingual learners, including Alaska Native students, practice and reflect on asset-based instructional practices within sustained cycles of collaborative inquiry. Findings indicate that sustained collaborative inquiry within learning communities with relational trust can create spaces for teachers to take up asset-based practices, grow in agency, and bridge the theory and practice divide.