 This study explored the complex systems that drive non-communicable diseases, NCDs, and related inequalities in the United Kingdom. It involved four workshops with key stakeholders from across the country, including government officials, academics, and community members. The participants identified healthy environments as an important emerging area for NCD prevention and emphasized the need for a comprehensive communication strategy. They also highlighted the importance of early engagement of diverse stakeholders in a theory-based co-production process, which provides valuable context and relevance. Finally, they stressed the importance of elite actors such as ministers and public sector leaders in developing and implementing successful NCD prevention policies. This article was authored by Fian Lloyd-Williams, Rebecca Masters, Lyraj Hyceni, and others.