This action research study explores how co-developing school meals can be taken as a case for education for sustainable development, as integrated to home economics education. We analyse a seven-month-process of collaborative participation in a Finnish secondary school conducted with two home economics teachers, a school food manager, and students during a voluntary home economics course. Data include interviews, multi-professional meetings, and professional reflections of the named school staff members (N = 3), as well as students’ (N = 8; 7th grade; aged 13–14 years) learning diaries, interviews and feedback questionnaire. We develop the term shared food sense (joint understanding, collective application, re-definition of co-action) as a conceptual tool for analysing food-related learning outcomes of the collaborative process. Analyses focused on 1) tensions emerging during the participatory work and 2) outcomes achieved through negotiation and collaboration, including roles that became possible for students to enact. Results show that collaboration succeeded in offering young people opportunities to influence and voice their opinions of school meals, as well as novel modes of interaction across the school’s social. However, students’ experiences of the participatory work varied, and power hierarchies among the different participating groups remained rather unchanged, demonstrating tensions between ideals and realities of participation.