Sodastream, According to Table 21B of the Examiner Handbook it is a Staff FE for FE CPL, FIE for FE PPL. If you also hold a CRE then it has to be a Staff FE, TSI or FOTI.
So it looks like a test with an FIE will do which will save you the thousand and fifty pound I just paid for a CAA observation to extend my authority.
I can thoroughly recommend the guys at Ontrack Aviation for getting you back up to speed and through the test.