While critical realist (CR) ontological and epistemological perspectives and research approaches are becoming more widely adopted by higher education researchers, the scope of research is relatively limited, and novice researchers in the area still struggle to create rich, in-depth, and critical accounts of these approaches 'in action'. This article provides an account of teacher-researchers' exploration of these perspectives in the context of an important aspect their everyday teaching practice -- the design of effective curricula and learning environments. The context is research that focused on the design, evaluation, and enhancement of learning environments intended to facilitate students' development of design thinking expertise. The article outlines the researchers' CR paradigm positioning and implications for methodologies used to gather, analyse, and theorise data about the response of design and business students to three iterations of a design thinking learning environment. The research involved action research that integrated survey, case study, and theorising methodologies. Examples of data, analyses, and explanatory theory are provided to give insights into specific research tasks and their outcomes. Possible explanations for the findings and their implications for attempts to enhance the learning environment are considered from a CR perspective along with challenges that deploying these approaches may entail.