Give everything an identity
Give each delivery, batch and finished product a code or date that stays with it, including part-used packs and food moved into other containers.
A decanted tub still carries the delivery's lot or date, so nobody has to guess which delivery it came from.
Ingredients are tipped into unlabelled tubs, and the lot on the carton goes in the bin with the carton.
's catering code asks for each container to show its production date, food type, establishment and lot. Keep raw materials, primary packaging, work in progress and identified too, because each one can be the source of a question.