In this study, we are exploring the development of professional learning of nearly qualified teachers, here referred to as prospective teachers, during their subject teacher education at a Finnish university. From a teacher educator stance, we aim to understand how teacher education practices can support prospective teachers' professional learning. The research question guiding our study is: How are prospective teachers portraying their professional learning by making use of a self-reflective portfolio? The data analysed consists of self-reflective learning portfolios written by prospective subject teachers as a course assignment in a course in general didactics. Drawing on a practice theoretical perspective, the analysis highlights how activities and assignments supporting both individual and collegial learning can be arranged during pre-service teacher education, and how prospective teachers can achieve a sense of collaborative and dialogic professional learning. The results contribute to discussions about promoting sustainable professional learning for both prospective and in-service teachers.