A traditional fermented food, oncom, produced in Indonesia from soymilk by-products, was studied to understand the molecular basis of fungal waste-to-food conversion. Using a multi-omics approach, researchers identified Neurospora intermedia as the dominant fungus in oncom. This fungus degrades pectin and cellulose during fermentation and is genetically distinct from other fungi associated with human-generated by-products. N. intermedia can grow on various by-products, including fruit and vegetable pomace and plant-based milk waste, and does not produce mycotoxins. It can create foods that are positively perceived by consumers outside Indonesia. The study highlights the potential of fungal fermentation for converting waste into nutritious and delicious foods, with implications for improving food sustainability and security. The research also emphasizes the importance of preserving traditional food practices in the face of industrialization and global change. The findings suggest that N. intermedia could be a valuable tool for future waste-to-food upcycling applications.A traditional fermented food, oncom, produced in Indonesia from soymilk by-products, was studied to understand the molecular basis of fungal waste-to-food conversion. Using a multi-omics approach, researchers identified Neurospora intermedia as the dominant fungus in oncom. This fungus degrades pectin and cellulose during fermentation and is genetically distinct from other fungi associated with human-generated by-products. N. intermedia can grow on various by-products, including fruit and vegetable pomace and plant-based milk waste, and does not produce mycotoxins. It can create foods that are positively perceived by consumers outside Indonesia. The study highlights the potential of fungal fermentation for converting waste into nutritious and delicious foods, with implications for improving food sustainability and security. The research also emphasizes the importance of preserving traditional food practices in the face of industrialization and global change. The findings suggest that N. intermedia could be a valuable tool for future waste-to-food upcycling applications.