The most common distinction within research in metacognition, is between metacognitive knowledge and metacognitive skill. This distinction leads to a teaching dilemma: which aspect to prioritise? As part of an enactivist study, I analyse the development of student metacognition in one teacher's mathematics classroom. While it is possible to view events in terms of metacognitive knowledge and skill, I argue that metacognition can also be seen as a way of teaching and learning that occasions a transformation of classroom discourse and practice. From this perspective, metacognition is a meta-category, encompassing both knowledge and skill but not reducible to those components and, hence, avoiding the teaching dilemma.