Old man’s attempt to make some dough (6)
I believe the answer is:
'some dough' is the definition.
(pastry is a kind of dough)
'old man's attempt' is the wordplay.
'old man's' becomes 'pas' (both can mean father).
'attempt' becomes 'try' (I've seen this before).
'to make' acts as a link.
(Other definitions for pastry that I've seen before include "Dough used in pie-cases" , "Cake - tart" , "Sweet baked dough" , "Dough made for pies, etc." , "See 7 Down" .)