This paper describes a participatory pastcasting workshop designed using action-oriented design research methods in close collaboration with practitioners from Omställningsnätverket (the Swedish Transition Network) as co-researchers. The paper deepens the theoretical understanding of how to implement pastcasting, a novel addition to futures studies methodologies aimed at societal transformation. We outline the process of designing the workshop format and insights from running the workshop in two different locations in Sweden. We propose that exploring complex problems such as climate change as if they have already been solved in an alternative, more desirable present and then imagining what we did to address them in the recent past is liberating and generative of ideas for action. We argue that this methodology is a powerful addition to other futuring techniques as it concretises urgently needed societal transformations and brings them closer to people and their communities.