dried food
薧 centers on food that has been dried for preservation. The meaning is narrow and concrete, referring to dried provisions.
薧 combines 艹 (grass/plant) with 死 (death), suggesting plants that have died and dried. The inner components 亠, 口, 冖 may be remnants of a phonetic or semantic element, but the exact historical development is uncertain.
The grass radical 艹 on top and the death radical 死 at the bottom paint a picture of plants that have died and dried out, becoming dried food.
For コウ, imagine a cook drying food: cook -> コウ, and the dried food is ready for storage.