I know EASA have stipulated a minimum of 3 training sessions if expired a certain period of time etc.
EASA have not stipulated anything, they have simply offered some optional guidance that has caused more trouble than it's worth. A proposed amendment to the AMCs, contained in NPA 2016-16 removes the guidance and changes the wording to emphasise that the amount of training is entirely at the discretion of the ATO.
Any organisation that offers a training course without conducting any kind of assessment of current ability is clearly incompetent or worse and should be avoided.