Minutes are the formal record of decisions taken at a meeting and presenting them for approval and signing by the Chair confirms their accuracy. They only become the formal record of the meeting from a legal perspective once signed. There is no legislation that states that they must be signed "at the following meeting" although clearly that is preferable. It might not always be possible, however, if for example there is an additional meeting in quick succession or if the clerk or minute taker is unwell or away. If the council is an exempt one (i.e. turnover less than £25,000 and therefore subject to the Transparency Act), a draft at least must be published within a month so it is not unreasonable to expect this to be the expected standard.
What the clerk "wants to do" and what you expect of him/her is your decision (within reason!) as a council. I would certainly expect minutes produced for approval at the next meeting unless there are exceptional circumstances.