This research introduces an innovative approach to mycelium-based composites (MBC) in architectural design by integrating food production into the material cultivation process. Departing from conventional MBC projects that focus on material innovation, this research valorizes fungal cultivation waste to create dual-purpose building components. Our MBC prototypes use prototyping techniques, including mesh discretization, strip paneling, and timber kerfing, to demonstrate the ability to support mushroom cultivation, achieve greater form complexity than existing MBC architectural applications, and eliminate the need for temporary formwork. This dual-purpose strategy offsets cultivation costs, minimizes environmental impact, and incorporates agricultural byproducts into the architectural process, further aligning MBC architectural development with circular economy principles.