This paper contributes to research on the growing expectation of hospitality businesses to implement sustainability strategies. By using the theoretical framework of professional knowledge cultures, as discussed by Nerland [Nerland, M. (2012). Professions as knowledge cultures. In Professional learning in the knowledge society (pp. 27-48). Brill/Sense], together with concepts of leadership and management, the study presents a novel approach. The aim is to explore the knowledge culture and the processes of learning and leadership formation in the restaurant industry to understand how these impact sustainable decisionmaking in restaurants. Through a narrative method, a typical industry career is illuminated, which mirrors the route to becoming a leader while adopting sustainability strategies. One podcast interview was used as research material to introduce a new data source derived from social media. The sampling considers the relevance of the narrators' knowledge and experience of the chef's profession and is therefore representative of a naturally occurring data. The analysis, based on knowledge culture, leadership practices, and sustainability, shows that the size of the restaurant matters for financial and socially sustainable decision-making. This is explained by the production flow in large organizations, which depends on calculated and effective work methods. Environmental sustainability strategies appear as a personal concern and are thereafter transformed into the knowledge culture, identified as a normative leadership.