This paper explores using design methods to examine ethical challenges in complex systems, specifically relating to technology design, policy, and governance surrounding new forms of data sharing and collaboration in food supply chains. In a research-through-design process, we developed speculative methods to examine how the incorporation of new technologies raises ethical considerations such as bias, transparency, and governance challenges in this sector. Design fiction artefacts were developed with an interdisciplinary team and assessed using the Moral-IT card deck. Through this process, we explored potential shortcomings, trade-offs, and dilemmas relating to speculative food data-sharing systems. The design methods enabled greater understanding of multifaceted challenges, supporting ethical practice in future design implementation and policy.