There is significant interest in designing technologies for the food system, from agricultural modeling tools to apps enabling humans to assess nutritional value of various food choices to drones for pest detection. However, a good food system must be a sustainable one. There is an urgent need for deliberation and thoughtfulness in designing for both technologies that support existing food systems and new modalities that work towards more sustainable food systems. This workshop will bring together HCI researchers, designers, and practitioners with an interest in exploring what constitutes a sustainable food system, as well as defining the role of HCI in this domain. Our key objectives for this workshop will be to identify what opportunities for design and collaboration exist and to lay the foundation for an active foodCHI community.