How can we inspire service innovation through the co-design of public sector healthcare delivery particularly when facing a large and complex challenge? The design and development of a new prototype food service to address malnutrition in older adult hospital patients is used as a case study. It describes how methods used predominantly by designers have been adapted to empower, train, inspire, facilitate and guide not only the multi-disciplinary research team - including food scientists, nutritionists, medical sociologists, ergonomists, and technologists - but also service users and providers. The co-design process is based on the idea that much innovation comes from creating a blend of ideas from multiple sources and that the design of the research can influence the degree of innovation. This paper describes the approach and process that has provided the research team with valuable findings, insights and ideas crucial to successful service redesign and innovation and which is resulting in a new food service prototype.