In this article, we describe a collegial case study conducted in one Finnish university during the last field experience in a primary school teacher education program and discuss pedagogy of supervision from university supervisors' perspectives. The aim of the study was to clarify the role of university supervisors and try out a collegial supervision approach to combine theory and practice in a field experience. We aimed to develop student teachers' understanding of curriculum as an enacted phenomenon in which they have agency, and enhance their understanding of the development of language skills when working with young children. Our supervision was based on the importance of situated learning and Kolb's experiential learning model. The results showed that a theory-based approach is possible and collegial supervision can add extra value to supervision. The student teachers became more aware of the different levels of curriculum and their meaning in teachers' planning processes. They also gained more comprehensive understanding of primary school teachers' possibilities to develop children's language skills every day and in all subjects. (Contains 2 figures and 1 note.)