This article reports on research methodology used for a case study investigating public health nutrition engagement in food regulatory policy processes in Australia. It aims to explore methods used and outline a model for how researchers can promote participant recall and accuracy. A set of key documents identified as relevant to voluntary food fortification policy (VFP) were analysed using Bacchi’s ‘What’s the problem represented to be?’ approach. The results informed a series of present-day, semi-structured, in-depth telephone interviews with experts in VFP. The major epistemological difficulty was the necessary reliance upon participant memory. Consequently, oral history methods were used to aid key informant recall. Several participants noted a benefit for their recollection of events from the tools employed. The experiences and approaches outlined in this article contribute to the toolkit needed when investigating historical events and may provide a useful model for other nutrition-related policy research.