The interplay between mathematics teachers' beliefs and practices has been widely investigated and research has examined how teachers' beliefs about mathematics, teaching and learning change when participating in continuing professional development (CPD). In this paper, I track teachers' self-reported beliefs and practice changes as they participate in a 1-year CPD programme intended to support them in "learning to teach mathematics through inquiry" (LTMI). LTMI is a blended programme that integrates two phases: summer workshops and monthly follow-up meetings held during the scholastic year. Using a case-study design, data focusing on self-reported beliefs and practices were collected, using questionnaires and interviews, from three teachers at different stages: before, during and at the end of the CPD. Results show that, following teachers' participation in summer workshops, they reported stronger connectionist beliefs. However, by the end of the CPD, while their connectionist beliefs remained strong, teachers reported increased discovery beliefs. Discovery beliefs were consistent with their reported changes in teaching practices. It appears that, in changing from transmission to inquiry teaching, these teachers adopted a non-interventionist and non-interactionist discovery teaching approach. This finding has implications for the design of CPD and, hence, the need to offer a supportive structure that helps teachers to recognise and address the limitations of their practices, along their journey to change towards more inquiry teaching.