Chaps regularly tucked into food made from mould (3-4)
I believe the answer is:
die cast
'mould' is the definition.
(I've seen this before)
'chaps regularly tucked into food' is the wordplay.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
'tucked into' is an insertion indicator.
'food' becomes 'diet' (diet is a kind of food).
The alternate letters of 'chaps' are 'cas'.
'cas' placed within 'diet' is 'DIE-CAST'.
'made from' is the link.
(Other definitions for die cast that I've seen before include "Found" , "Mould into shape" , "model" , "point of no return passed" , "Moulded from molten metal" .)