What is the best way to organize the collection and distribution of money among employees to cover monthly food expenses?

If money for monthly expenses is collected and one of you is authorized to spend it, then there is no harm in him taking the surplus for himself, provided that you are pleased and give your consent willingly. Otherwise, he must return it to you. It is preferable to return it to be spent in the following month, because silence might be out of shyness, not out of willingness. It is narrated in the Hadith: "The wealth of a Muslim person is not lawful [for another] except with his willing consent." There is a consensus that whatever is taken out of shyness, without willing consent, is not owned by the taker, because it involves compulsion by the "sword of shyness."