Scarcity of baked beans since Jesus was born (7)
I believe the answer is:
absence
'scarcity' is the definition.
(thesaurus)
'baked beans since jesus was born' is the wordplay.
I cannot quite understand how this works, but
an anagram of 'beans' is 'absen' which is within the answer.
This explanation may well be incorrect...
'of' acts as a link.
Can you help me to learn more?
(Other definitions for absence that I've seen before include "Cause of fonder heart?" , "form of inattention?" , "Want, lack" , "It's said to make the heart grow fonder" , "Failure to attend" .)